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Itching in the dog: why the dog is scratching and how to help him?

A dog's itching is an unpleasant sensation that triggers the urge to scratch.

Itching in the dog

This short definition, introduced in 1960 by the German doctor Samuel Hafenreffer, has not lost its relevance and is still used - both in human and veterinary medicine.

Indeed, itching is an unpleasant sensation; I would even add that it is one of the most troublesome symptoms faced by our four-legged patients.

On reading this succinct and rather harsh description of itching, you might think:

well, itch like itch, nothing terrible.

Yet most of us know that itching can be harder sometimes than pain.

That itching it is not only an unpleasant sensation, but it can be a whole arsenal of unpleasant sensations from tenderness, through hypersensitivity, irritation, burning and even pain.

The matter is further complicated by the fact that it may not be felt only on the skin, but also on the mucous membranes of the natural openings of the body (including the conjunctiva) and the initial section of the respiratory system.

Yes, itch it can be not only unpleasant, but also truly irritating.

No wonder that itching - especially the intense or long-lasting one - is one of the most common reasons for consultations in veterinary offices.

And just about itching in dogs will be treating this article. You will learn from it:

which actually causes the dog to scratch,
you will find information about the most common diseases or pathological conditions accompanied by itching,
you will learn about therapeutic options that will help to a greater or lesser extent bring relief to your scratching dog.

So, without extending the introduction too much, I invite you to read this study.

Why does the dog feel itchy?
Types of itching in dogs
Why the dog is scratching or the causes of itching in dogs
Signs of itching in a dog
Consequences of itching
Diagnostics for the cause of itching
- Dermatological interview
- Assessment of itching in a dog
- Description of the animal
- Clinical examination
- Positive ear-foot reflex
- Diagnostic test
Treatment of itching in a dog
- External treatment of itching
- Methods of Topical Treatment of Pruritus in Dogs
- Characteristics of substances included in topical preparations
Dog allergy
Flea allergy: flea allergy dermatitis
Atopic dermatitis
- Causes of atopy in a dog
- Symptoms of allergic dermatitis
- Diagnosis of atopic dermatitis in a dog
- How to deal with atopic dermatitis?
Food alergy
- Symptoms of food allergy in a dog
- Elimination diet when food allergy is suspected
- Are there any easier alternatives to an elimination diet?
- Treatment of food allergy in a dog
Infections
Purulent dermatitis
- The causes of purulent dermatitis
- Classification of purulent dermatitis
- Symptoms of purulent inflammations of the dog's skin
- Diagnosis of purulent dermatitis
- Treatment of pyoderma in a dog
Dermatitis caused by Malassezia
- Clinical symptoms of malasiosiosis
- Treatment of malasiosiosis
Flea infestations
- Flea infestation treatment
An invasion of scabies
- Clinical symptoms of sarcoptosis
- Treatment of sarcoptosis
Ear mites
- Treatment of otodectosis
Chelyletelosis
- Treatment of cheletelosis
Thrombiculosis
- Treatment of thrombiculosis
Demodicosis in a dog
- Treatment of demodicosis
Licking granuloma
- Treatment of a licking granuloma
Other diseases that may be accompanied by itching

Why does the dog feel itchy?

Why is the dog scratching?

The organism of an animal (as well as a human) constantly receives mechanical, thermal, light or chemical stimuli from the internal and external environment.

It does this through specialized receptors that collect these impulses and transmit them to the central nervous system. Pruritus receptors are located in the epidermis, where the dermis transitions into the epidermis, and in the dermis.

After the nerve endings are stimulated by specific mediators, the stimuli are transmitted through nerve fibers to the central nervous system.

Itching is the result of irritation of two types of itch receptors:

the myelin-free C-fiber ends (the so-called. C-nociceptors),
A-delta fibers located in the basal layer of the epidermis and in the papillary layer of the dermis.

As a result of stimulation by a pruritic factor (it can be a mechanical, thermal, light stimulus, but most often chemical), the free nerve endings of C fibers send signals to the spinal cord, from where they are then conducted to the subcortical centers, where they can be extinguished or sent to the cerebral cortex ( then they are consciously perceived as itching, which in turn triggers a scratching reflex).

This sensation of itching may be the result of the direct action of the above-mentioned stimuli on the skin, or it may also be due to the indirect action of pruritic mediators, released by the body's cells, such as, for example:

mast cells,
keratinocytes,
lymphocytes.

This is important because understanding the pathomechanisms responsible for itching allows for the selection of an effective therapy.

The pruritic mediators include:

Direct mediators:
- histamine,
- acetylcholine,
- prostaglandins,
- endothelin,
- some cytokines (IL-1 to IL-11, TNF-α, eosinophil products);
Indirect mediators:
- released during the degranulation of mast cells (histamine, tryptase, serotonin, prostaglandins) and keratinocytes (acetylcholine, histamine);
- proteases (tryptases, chymases, carboxypeptidases, papain, kallikrein);
- neuropeptides (substance P, bradykinin, endothelin, neurokinins, somatostatin, corticotropin releasing hormone (CRF), vasoactive intestinal peptide (VIP), cholecystokinin, neurotensin, and others);
- capsaicin.

As you can see, the pathomechanism of pruritus involves numerous factors, the identification and elimination of which can be really difficult, which is often met with dissatisfaction on the part of a caregiver scratching a pet, and frustration on the part of a veterinarian.

If the pruritus is caused by a primary skin disease, it is usually possible to diagnose quickly and implement effective treatment.

Unfortunately, in many cases the pathomechanism of pruritus is more complex, and it is associated with the coexistence of many causes causing it.

This is what happens, for example. in the course atopic dermatitis or uremia.

If the dog's intense scratching is a symptom of a systemic disease, the therapy helps to alleviate the itching, but usually such diseases are chronic and worsening, which necessitates symptomatic treatment of the itch.

Types of itching in dogs

Due to the complexity of the nature of pruritus, it has been classified in a number of different ways over the years.

Currently, the most common division is:

Classification due to the mechanism of pruritus (based on. the classification of pruritus according to Twycross et al. and Teresiak-Mikołajczak et al.)

Pruritoceptive / cutaneous pruritus - depends on pruritus receptors and is caused by pruritus mediators (pruritogens) such as histamine and other amines, proteases, growth factors, neuropeptides, opioids, prostaglandins and cytokines.
It accompanies, for example,. insect bites if the action of skin irritants.
Neuropathic pruritus - is the result of damage or disruption of the nervous ascending pathway.
An example is itching when infected with a virus Herpes.
Neurogenic pruritus - originates from the central nervous system but is not associated with neuronal damage (as opposed to neuropathic pruritus).
It is pruritus associated with systemic diseases, and it is caused by neuropeptides and opioids.
Examples of associated diseases are:
- liver failure,
- chronic renal failure.
Psychogenic pruritus - associated with behavioral and mental disorders.

Classification according to the duration of symptoms

Acute pruritus - lasting less than 6 weeks.
Chronic pruritus - lasting more than 6 weeks.

Breakdown by cause (according to IFSI - International Forum for the Study of Itch)

Group I - pruritus caused by dermatological diseases without previous skin changes.
Group II - pruritus occurring in diseases other than dermatological diseases, such as organ, neurological, psychogenic, psychosomatic diseases.
Group III - chronic pruritus accompanied by secondary skin lesions as its effect (e.g. quarrels, scabs, lumps, lumps, nodules).

Classification according to where the itching is felt

Localized pruritus - affects a specific area of the body.
Generalized pruritus - itching spreads over the whole body.

Why the dog is scratching or the causes of itching in dogs

Causes of itching in dogs

Itching is a sensation that accompanies many diseases.

It is most often associated with dermatological problems and initially diagnostics are based on this assumption, but pruritic diseases are also a whole group of disorders and general diseases, the manifestation of which also includes the skin.

So let's see what pathological conditions can be accompanied by itching.

The most important causes of itching in dogs include:

atopic dermatitis,
food alergy,
hypersensitivity to parasites:
- fleas,
- hollow scabies,
- Cheyletiella,
- ear scabies,
Malassezia dermatitis,
pyoderma (caused by Staphylococcus).

Very often, food atopy or allergy is complicated by bacterial or yeast infections, hence the diagnostic path leading to the isolation of one primary cause of pruritus can be tedious and often very frustrating.

Signs of itching in a dog

Itching symptoms in the dog

For itching, your natural reaction is to scratch - that is, mechanically stimulate the itchy area to change how you feel it.

This way of reacting is completely different than in the case of pain - here comes the desire to avoid, to escape from the factor causing it.

It is much easier to notice itching in dogs than in cats, which are incredibly secretive animals and do not manifest (up to a point) such unworthy behavior as scratching the body with their own claws.

However, itching is not just scratching.

There are also other ways to get rid of this unpleasant feeling that many dogs (especially those with a chronic problem) have mastered.

The most common of them are:

Excessive licking of itchy areas of the body, biting of the hair coat (sometimes resembling grooming), skin biting which is often seen with itching of the peripheral limbs.
Rolling around, rubbing itchy parts of your body against objects, becoming scratched.
Tobogganing - when itching around the anus.
Frequent head banging, paw rubbing around the auricles - with itching of the ears.
Rubbing with paws on the nose or around the eyes - with itchy head.

It is often accompanied by changes in the skin and hair in the form of:

hair thinning, combs and even baldness,
matting and tangling of the hair,
abrasions, wounds, darker skin color,
lumps, pustules and scabs,
erythema on the skin,
body odor,
serous or purulent exudate.

The intensity of a dog's itching may vary throughout the day. It can be noticeably larger:

in the night,
at elevated ambient temperature,
with reduced skin hydration,
states of mental agitation.

Consequences of itching

wiping, dulling and breaking the hair,
thinning and even baldness,
change in color of the coat at the point of licking (the coat may become rusty-brown),
skin inflammation,
self-damage,
bacterial and fungal infections,
intensive and long-lasting scratching may be the cause compulsive states and fixation of licking even when the pruritus is eliminated.

Diagnostics for the cause of itching

Diagnostics

If you are looking after a scratching dog, the first thing you should do is be patient.

A lot of studies have been written about pruritus in dogs, but it is still a very serious diagnostic problem. It is related both to the mechanisms responsible for its formation, factors complicating the typical course of diseases with pruritus, as well as the different degree of its perception by different animals.

Therefore, the road to truth is often very bumpy, full of turns and dead ends.

Often frustrated animal keepers give up halfway through the diagnosis and go to another doctor who repeats the tests already carried out, starting the journey anew.

However, in order to introduce you - dear reader - this difficult and time-consuming process of finding the cause of itching, I will introduce you to its individual stages.

During the first visit to the veterinarian, it is often possible to find the main cause of itching and treat it successfully.

If e.g. the dog scratches itself due to the presence of fleas, diagnosis and treatment should not be difficult. But what if the animal has atopy or allergy, and in addition, complicating infections have appeared?

Let's follow a step-by-step process for determining the cause of itching in dogs.

Dermatological interview

At the beginning of the visit, the doctor will interview you.

In other words - it will ask you a lot of questions that you should try to answer as accurately as possible.

The doctor will ask you about many important issues, and an example of a list of questions is presented below.

To make things more difficult, the information you provide will not rule out any of the potential causes of itching, but it will allow you to organize and arrange them in a specific order (according to probability). Thanks to this, it will be possible to gradually eliminate the suspected causes of pruritus. So expect the following questions:

When and under what circumstances the dog was found to itch?
This question is very relevant especially in the case of recurrent inflammatory skin diseases such as diseases allergic and atopic dermatitis, in the course of which symptoms (including pruritus) manifest themselves seasonally.
Whether the pruritus occurs seasonally?
Whether a dog's scratching occurs at certain times of the year is important in identifying the cause of the itch. If your dog shows signs of scratching, e.g. only in the warm season, it is most suspect atopy and hypersensitivity to external parasites.
The presence of itching throughout the year does not exclude atopy or even allergy to fleas, but it adds to the group of suspects, e.g. food allergy.
Age at which itching symptoms appeared.
This information can be useful because many itchy diseases appear around a certain age in the dog.
Of course, it cannot be categorically stated that e.g. demodicosis affects only young animals. However, in the diagnosis of pruritus, the likelihood of disease is initially seriously considered.
In addition, some dermatological diseases develop gradually, and their symptoms increase with the age of the animal.
- Dogs under the age of 1. years of age scratch themselves most often because of hypersensitivity to parasites (including demodecosis). They have less atopy or food allergy.
- Between 1. a 4. year of life in fact "anything can happen ", but atopy at this age, the ranking of the most common pruritus units wins.
- Ages 6+. age food alergy becomes more frequent than atopy.
- In elderly patients it is considered endocrinopathies (e.g. hypothyroidism) with secondary bacterial or fungal overgrowth.
Since when the dog is with the current guardian? Where it was taken from? (shelter, kennel, street?) Whether - in relation to the puppy - similar changes are observed in his brothers and sisters from the litter?
Whether your dog is only itchy, or is there any noticeable symptom? What the first symptoms looked like and how they developed?
Has the itch been treated? When? Using what drugs and doses? With what effect?
Whether the pruritus appeared before or after other symptoms?
In what conditions does the dog stay? To what places is he taken for walks?
What dog food does he get? Is it satisfactory??
Are there any gastrointestinal disorders? Diarrhea? Vomiting?
Have there been any changes in the dog's appetite? Is it elevated? Is he weakened?
Whether the dog has increased thirst?
Has the animal become lethargic, even sleepy??
Whether muscle weakness, exercise intolerance is noticeable?
Whether (in non-castrated animals) the sexual cycle is normal?
Are there any respiratory symptoms? Sneezing? Cough? Nasal discharge?
Is the animal undergoing regular prophylaxis against internal and external parasites??
Whether the animal has any other diseases that are not related to the skin?
Whether the dog is getting any medications? What? In what doses and with what frequency?
Are there other animals in the immediate vicinity of the dog?? What? Are they also seeing similar symptoms??
Whether itching or skin lesions are seen in humans contacting the dog?

Assessment of itching in a dog

Your veterinarian must work closely with your pet handler to assess the itch as accurately as possible - its location, intensity and frequency.

Of course - on the basis of changes in the quality of the hair and specific changes in the skin - it can indirectly conclude about the severity of itching and its location, but in order to correctly assess itching in dogs, tests based on a multi-level scale are used.

Therefore, your doctor may ask you to help determine the severity of the itch.

Below are some sample tests for this purpose:

The itch rating scale according to Rybnicek et al.

0-2 - healthy dog.
2-3 - itching is very rare, episodes of scratching are sporadic, but according to dog handlers, they are more frequent than before the skin disease.
3-5 - pruritus is rare, but is clearly more frequent; does not scratch while sleeping, playing or eating.
5-7 - moderately frequent pruritus; regular episodes of scratching even at night, but the dog does not scratch when playing or eating.
7-9 - itching frequent, long-lasting scratching episodes that also occur at night and while eating and playing.
9-10- itching is very frequent, continuous; the dog does not stop scratching even when visiting the office; In order for the animal to stop scratching, it is necessary to apply physical stimuli to make it stop.

Assessment of the intensity of pruritus according to Burton g. Et al.

0 - no itching.
1 - moderate itching - sporadic episodes lasting no longer than 30 seconds.
2 - moderate pruritus - itching is more frequent, but the episodes are short-lived, usually approx. 30 seconds.
3 - severe itching - higher frequency and intensity of scratching, the dog is restless, interested in scratching specific areas for more than 30 seconds.
4 - extreme itching - the dog is constantly scratching and it is difficult for the handler to stop scratching.

Assessment of the frequency of pruritus according to Burton et al.

0 - no itching
1 - there are 1-2 scratching episodes within 30 minutes
2 - 3-4 episodes
3 - 5-6 episodes
4 -> 6 episodes

These tests are useful not only for diagnosing the causes of itching, but also later to help assess the effectiveness of treatment.

Description of the animal

The next step is to identify certain predispositions that may influence the development of certain dermatological diseases.

These include, for example racial predisposition.

Pruritic dermatoses may be particularly common in certain breeds. For example:

multi-fold dermatitis likes short-skulled dogs and those with skin folds, e.g.:
- boxer,
- French Bulldog,
- English bulldog,
- Shar-pei,
- mastiff.
on the other hand atopic dermatitis often affects breeds such as:
- boxer,
- Dalmatian,
- Irish setter,
- German Shepherd,
- French Bulldog,
- West Highland White Terrier,
- Labrador,
- golden retriever,
- dachshund.

Racial predisposition is of course very important factors, which in many cases immediately make you suspect the disease, but these first associations may unfortunately lead the doctor astray.

It is obvious that in a French bulldog or West Highland White Terrier, atopy should be considered as the cause of itching (because it is so common in them), but what - if the doggie just caught scabies?

The lists of racial predispositions to various diseases are really long, in addition, they change depending on the popularity of a given race, geographic location and time.

The truth is that any dog can be atopic, have a food allergy, catch fleas or mites, suffer from a bacterial or fungal infection.

Therefore, regardless of breed and other predispositions, a thorough and methodical clinical examination should always be carried out and each scratching dog should be treated the same.

Age of the dog.

Demodicosis usually occurs in young dogs, symptoms of atopy are noticed after reaching the age of one.

Clinical examination

Atopy and food allergy they may look identical to the examiner.

The temptation to classify these diseases on the basis of the presence of changes in a particular region of the body should be resisted.

Hypersensitivity to fleas usually shows up in the back of the dog, with the classic symptoms:

erythema,
alopecia,
follicular dermatitis on the dorsal surface of the tail epiphyses.

You should also check belly button, because many animals have changes right there.

Scabies usually associated with auricles, elbows and the sides of the body, but not always.

In fact, any dog that itches can have scabies.

Cheyletiella usually shows up as thick, dry scales on the back.

If itching mainly affects interdigital spaces account is taken of:

atopic dermatitis,
food intolerance or allergy,
contact dermatitis,
demodicosis,
thrombiculosis,
pyoderma,
malasiasiosis.

If the pruritus is mainly localized in the ear area:

inflammation of the outer ear caused by bacteria or yeasts,
atopic dermatitis,
food allergy,
contact dermatitis,
ear scabies,
thrombiculosis.

Itching of the dog's facial area may be a symptom of:

atopic dermatitis,
food allergies or intolerances,
contact dermatitis,
demodicosis,
purulent dermatitis,
malasiosiosis.

Itching in the area groin and lower abdomen:

atopic dermatitis,
food intolerance or allergy,
contact dermatitis,
pyoderma,
malasiosiosis.

Itching area ridge:

flea allergy dermatitis,
the presence of fleas,
cheylletelosis,
head lice.

Positive ear-foot reflex

It is checked by rubbing or lightly scratching the ear.

If in response the dog immediately starts scratching with the paw that is on the same side as the scratched auricle, the reflex is considered positive.

It usually accompanies scabies, while the negative ear-foot reflex is associated with most pruritic diseases.

This tool may be deceptive, but it is always advisable in the presence of a positive result antiparasitic treatment.

However, you should never rule out scabies based on a negative result.

Diagnostic test

Any dog scratching should have a few simple office tests to rule out the most likely and common causes, such as external parasites, bacterial or fungal infections.

In fact, these factors should in fact always be considered and treated appropriately, whether or not it is caused by other, more serious complaints. The mere fact of dealing with e.g. current infection can cause reduction of itching by 60-70% within two weeks.

These infections very often occur secondary to atopic dermatitis or food allergy, and their appropriate treatment is equivalent to that of the primary disease.

Therefore, do not be discouraged if the doctor first "starts" to treat the infection, leaving the allergy for later. Sometimes it is even necessary to pave the way, cleanse and eliminate additional symptoms in order to reasonably approach the therapy of the underlying disease.

Pap test for bacteria and yeast

Pyoderma is a serious cause of pruritus that can complicate the diagnosis of an allergic disease.

Skin infection may also be the leading cause of itching in patients with hypothyroidism.

Skin scrapings are tests aimed at:

scabies,
cheyletiella,
Demodex.

It is worth remembering that a negative result does not exclude the presence of any of these parasites.

If, however, mites are found, treatment should be instituted.

In this case, the continuation of further diagnosis may be discontinued as it is reasonable to introduce targeted treatment.

Treatment regimens vary:

can be used selamectin 3 times every 2 weeks,
the alternative is milbemycin at a dose of 2 mg / kg m.c. Once a week for a month,
or ivermectin 300 mcg / kg weekly for a month (NOTE: ivermectin cannot be administered to dogs with a mutation in the MDR1 gene).

The selection of additional diagnostic tests is based on the suspicion of a given disease.

Breeding for pathogenic fungi and possible antifungal treatment: ketoconazole or fluconazole at a dose of 5 mg / kg m.c. 1 time a day for 30 days.

Treatment should be supplemented with a weekly bath in a dog's antiseptic shampoo, containing:

chlorhexidine,
ketoconazole,
miconazole,
benzoyl peroxide.

8-week elimination diet followed by provocation feeding

Such a procedure may be recommended at the first visit, if the results of the tests carried out in the office so far did not bring the expected information, and the doctor suspects a food allergy.

Skin biopsy

It is indicated when other diagnostic tests have not provided any information about the cause of the pruritus, in addition, the patient does not respond to treatment and the disease is progressing.

An early biopsy may be considered when the lesions look unusual.

After 2-4 weeks, your doctor will want to see if the problem of a bacterial or fungal infection has been resolved.

If there is no response to treatment and bacteria are still present in the Pap smear, perform bacteriological examination with an antibiotic pattern.

It should also be checked that the anti-parasitic prophylaxis is properly carried out.

Allergy tests

If after 4 weeks there are no signs of bacterial or fungal infection or parasitic infestation, but symptoms of pruritus are present (they may not be as severe as before) - another suspicion is atopic dermatitis or food allergy.

In this situation, allergy tests can be performed.

8-week elimination diet

A properly conducted diet should be based on two pillars:

First of all, avoiding all possible triggers of an allergic reaction for 8 weeks (most often you choose one component of the diet, the most suspect).
Second, provocation with this particular ingredient at the end of the trial.

Any hypoallergenic diets, based on hydrolyzed protein do not have any magical properties that reduce itching.

These diets are designed to nourish the animal without provoking allergic reactions.

In addition, the caregiver must stop serving any snacks or foods that contain a potentially allergenic food component.

There is a catch in an elimination diet:

many pet owners expect that during these 8 weeks the itching of an allergic dog will disappear and will be able to firmly say that it was caused by a food allergy.

Unfortunately, that's not how it works. In fact, less than half of food allergy patients show any improvement in the first 4 weeks of using the new diet, and 1/5 may show some degree of itching in the last, 8 weeks.

Many carers at this time have doubts and return to the old eating habits of their charges.

And the diagnostic value of an elimination diet is less about judging how well the dog felt while on it.

What is more important, however, is how much the itch deepens after the provocative introduction of the allergenic food after its completion.

Patients allergic to chicken (for example) will show a recurrence of more intense clinical symptoms after an 8-week break and reintroduction into the diet.

And voila! We are allergic to this particular food ingredient. You can go back to the test diet.

If, on the other hand, the intensity of the itching in the patient does not change - then bravo! We have ruled out food allergy.

Seemingly simple, but in practice - it rarely works.

I have already mentioned that many caregivers give up without seeing the results of the introduced diet. Others, on the other hand, who have noticed a significant improvement in clinical symptoms, do not wish to introduce a provocative diet.

Control visit after 8 weeks

If our scratching dog has already cured infections (bacterial and fungal), parasitic invasions, food allergy has been ruled out, and the itching, as it was, is so - most likely we are dealing with atopic dermatitis.

Most likely, because it's not quite sure yet.

In this case, antiparasitic prophylaxis, local antiseptic therapy (shampoos, etc.) should be continued at the same time.) and to focus on treating atopy.

Treatment for your dog's itching may include:

steroid therapy (to reduce the inhumane level of itching),
antihistamines,
omega 3 fatty acids,
topical emollient therapy,
local anti-itching therapy,
cyclosporin,
oclacitinib,
specific immunotherapy.

Treatment of itching in a dog

How is itching in a dog?

The most important thing in treating itching is to recognize the underlying disease that causes it.

Thanks to this, causal treatment can be applied (e.g. APZS, food allergy, scabies).

It is also extremely important to identify complicating factors such as pyoderma or Malassezia.

Therefore, the following are the most important factors in the fight against itching:

antibacterial drugs,
antifungal drugs,
antiparasitic drugs.

Regardless of the cause, however, responsible for the appearance of itching, we want to quickly eliminate or at least reduce this unpleasant sensation.

The itching can be influenced on several levels:

Effects on skin receptors with the use of skin care preparations with a local protective effect and local anesthetics.
Effects on pruritic mediators:
- antihistamines,
- polyunsaturated fatty acids (to reduce the production of pro-inflammatory eicosanoids),
- glucocorticosteroids - they work on many levels, and their antipruritic use is mainly related to the anti-inflammatory effect:
  - reduce the production of IgE antibodies,
  - reduce the amount of skin mast cells,
  - stabilize cell membranes,
  - inhibit the degranulation of mast cells,
  - they inhibit some inflammatory mediators,
  - inhibit phospholipase A2 and eicosanoids.
Effects on the spinal cord and cerebral cortex:
- opioid antagonists,
- serotonin reuptake inhibitors.

In practice, therefore, the treatment of pruritus is carried out in several ways:

Causal action, aimed at eliminating the main cause of itching.
There will be drugs here:
- acaricidal,
- insecticides,
- antibiotics,
- antifungal drugs.
Treatments to reduce pruritus:
- antihistamines,
- glucocorticosteroids,
- cyclosporine,
- apoquel,
- serotonin reuptake inhibitors and others.
Polyunsaturated fatty acids.
The key nutrients that affect the condition of hair and skin are long-chain polyunsaturated fatty acids from the n-3 family (α-linolenic acid - ALA and the resulting eicosapentaenoic acid EPA and docosahexaenoic acid DHA) and n-6 (linoleic acid - LA and its derivatives: γ-linolenic acid - GLA and dihomo-γ-linolenic acid - DGLA and arachidonic acid - AA).
Among them, DHA and EPA acids deserve special attention, because they are highly effective in the treatment of itchy skin diseases. Their natural source is the fats of marine and oceanic fish. Polyunsaturated fatty acids are also available in the form of various supplements. They should be administered over a period minimum 8 weeks. A noticeable reduction in itching usually occurs at 40-80% of cases.
Pentoxifylline - is a phosphodiesterase inhibitor with many immunomodulatory properties.
Its action is based, inter alia, on reducing the production of TNFα.
Used as an adjunct in the treatment of atopic dermatitis in dogs at a dose of 10 mg / kg m.c. 2 times a day.

External treatment of itching

Topical treatment for the management of pruritus cannot be overestimated.

Systemic therapy, despite its undeniable value, is only part of the antipruritic treatment. The advantages of external treatment are really many:

medicines and care products applied externally have a much smaller effect on the animal's organism,
antiseptics do not bear the risk of developing resistant bacterial strains, as is the case with the use of antibiotics,
regular use of topical agents allows to shorten the treatment time, reduce the doses of antipruritic drugs, and thus reduce or eliminate the occurrence of undesirable effects of systemic drugs.

No wonder that the use of skin preparations has become an integral part of the treatment of not only pruritus, but also a part of the treatment canon of all dermatological diseases.

With topical treatments, fighting itching comes down to two basic issues:

Mitigating and anti-infective properties (antibacterial, antifungal, antiparasitic).
For this purpose, the following groups of preparations are used:
- Soothing and regenerating agents, which may include:
  - allantoin,
  - chamomile extract,
  - menthol,
  - panthenol,
  - aloe vera,
  - vitamins (biotin, tocopherol acetate),
  - polyunsaturated fatty acids.
- Anti-inflammatory and anti-itching medications, such as:
  - cutaneous antibiotics,
  - skin antiseptics, including:
    - benzoyl peroxide,
    - benzalkonium chloride,
    - chlorhexidine,
    - hexamidine,
    - hexetidine,
    - ethyl lactate,
    - chlorothymol,
  - antiparasitic preparations,
  - skin steroids,
  - local anesthetics.
Elimination of the secondary keratolytic state:
- keratomodulating action:
  - keratolytic agents:
    - salicylic acid,
    - lactic acid,
    - undecylenic acid,
    - transretinoid acid,
    - urea,
  - keratoplastic agents:
    - sulfur,
    - salicylic acid,
    - tar (tar, ichthyol, coaltar).

Methods of Topical Treatment of Pruritus in Dogs

Hydrotherapy

Bathing is of great benefit to a dog suffering from itching.

They not only cleanse the skin of impurities, dried exudate, scabs, dead epidermis and cellular debris.

They also provide cleansing and drainage of wounds and fistulas.

The bath stimulates blood circulation, cools the inflamed areas if necessary and reduces the severity of itching.

If, after bathing, we additionally apply occlusive substances on the skin (e.g. petroleum jelly, mineral or silicone oils), they will create a kind of film on the surface of the skin, a film that retains a layer of water directly next to the skin.

Hydrotherapy exerts undeniable therapeutic effects in pruritic animals.

Shampoo therapy

Shampoo therapy is an important element in the treatment of skin diseases, including pruritic diseases.

The selection of an appropriate shampoo depends on the nature of the underlying disease.

Antiallergic shampoos

They contain emollients and moisturizing substances:

fatty acids,
lipids,
phytosphingosine,
urea,
glycerin,
oat colloidal solution.

Anti-itching and anti-inflammatory shampoos

They may contain specific active substances, e.g.:

1% hydrocortisone,
0.001% flucinolone,
2% diphenhydramine.

Anti-parasitic shampoos

They usually include:

pyrethrin,
synthetic pyrethroids.

Currently rarely used - they are replaced by parasiticides in the form of spot-on.

Anti-seborrheic shampoos

They most often include:

salicylic acid,
sulfur compounds,
benzoyl peroxide,
zinc gluconate,
selenium sulfate,
tar.

Antimicrobial shampoos

The most common active ingredients in antibacterial shampoos are:

chlorhexidine,
benzoyl peroxide,
phytosphingosine,
ethyl lactate
iodine compounds
sulfur compounds.

Anti-fungal shampoos

Their main ingredients are miconazole, ketoconazole, but they can also contain chlorhexidine, phytosphingosine, sulfur and selenium compounds.

These shampoos are used to support the treatment of dermatitis caused by Malassezia yeasts, but are not suitable for the treatment of dermatophytosis (only in the form of adjunctive therapy).

Rinses

They can be used after therapeutic baths to enhance the anti-itching, moisturizing and antibacterial properties.

Powders

Powders have strong hygroscopic properties, drying the skin and reducing friction (especially between skin folds).

Recommended for skin care in purulent eruptions, especially in locations predisposed to irritation:

interdigital spaces,
the area of skin folds,
armpits,
groin.

Lotions

Lotions are suspensions of powders or other liquid substances.

They may include:

hydrocortisone,
betamethasone,
oat colloidal extract,
pramoxin,
chlorhexidine,
miconazole.

Spot-on preparations

The essence of their action is penetration into the skin film, which is the fat-sebaceous layer on the surface of the epidermis.

They accumulate in the hair follicles and sebaceous glands, from where they are then gradually released, covering the entire surface of the dog's skin.

Spot-on preparations are most often associated with a parasiticidal effect, but this form of drug application is also used for skin care, especially when its functions are disturbed.

Used to treat patients with keratolytic disorders and atopic dermatitis (products containing unsaturated fatty acids, phytosphingosine, etc.).

Aerosols

Aerosols most often contain emollients and moisturizing substances, but they can also be a form of administration of antiseptic or antiparasitic drugs.

The following substances are used in the antipruritic effect:

hydrocortisone,
triamcinolone,
phytosphingosine.

Creams

Creams (i.e. emulsions of fats and water) and ointments (water-insoluble mixtures of animal, vegetable or mineral fats) are used on smaller areas of the body.

Depending on the type of substances they contain, they may have the following properties:

keratolytic,
moisturizing,
antibacterials,
antipruritics, etc.

Gels

The gels, when applied to the skin, do not leave any film.

Gels from:

benzoyl peroxide, to treat:
- acne,
- blackheads,
- demodicosis,
salicylic acid and urea for the treatment of:
- finger pads and nose hyperkeratosis,
- elbow calluses.

Characteristics of substances included in topical preparations

Moisturizing action

Glycerol (glycerin)

Popular glycerin is a moisturizing, regenerating and oiling agent.

It has water-retaining properties, which slows down skin dryness and softens it.

It also facilitates the transport of nutrients into the skin.

Thanks to its properties, it reduces the intensity of itching, and the "side effect" is also the effect of polishing the coat.

Urea

Urea, which is a component of shampoos, is an effective keratolytic.

In higher concentrations, it has proteolytic properties and accelerates the absorption of fibrin.

It also has a moisturizing effect: it increases the hydration of the stratum corneum and the reproductive layer of the epidermis.

Lactic acid

It has mild keratolytic, antibacterial and moisturizing properties.

In addition, it stimulates the production of ceramides, which helps to rebuild the damaged epidermal barrier.

In higher concentrations, it has peeling properties.

Collagen

It has regenerative and moisturizing properties.

Creates a thin protective film on the skin surface, which increases water retention in deeper layers and protects against the penetration of external factors.

It improves skin elasticity.

Colloidal oat extract

It soothes irritations, reduces the intensity of itching, has a moisturizing and elasticizing effect.

Especially used in chronic itching skin diseases (allergies, atopy).

It nourishes and regenerates.

Paraffin oil

It is a colorless mineral oil, very often the base of various cosmetics (also for people).

It has moisturizing properties - when applied to the skin, it creates a protective film on it that protects it against water loss.

Petrolatum

It is not absorbed through the skin, therefore it is widely used as a base ingredient in many preparations and cosmetics.

It moisturizes, lubricates and soothes irritations, and additionally creates a protective layer on the surface of the skin.

Lanolin

It has moisturizing properties - it creates an occlusive layer on the skin surface, preventing excessive water loss.

It facilitates the penetration of nutrients into the skin, has softening and elasticizing properties.

It is widely used in the care of dry skin, soothes inflammation and accelerates healing.

Hyaluronic acid

It has strong water-binding properties, therefore it is used as a moisturizing agent.

It creates a film on the skin surface that protects the stratum corneum from excessive water loss. It has a smoothing and elasticizing effect on the skin.

Lecithin

It's an oiling agent.

Thanks to the ability to create lipids, it allows nutrients and vitamins to penetrate deep into the epidermis.

It protects the skin against excessive water loss and has a toning effect.

Antiseptic action

Benzoyl peroxide

As an antibacterial agent, it has a broad spectrum of activity.

It has keratomodulating, antipruritic, degreasing and comedogenic properties.

The keratolytic effect is provided by benzoic acid (which is a product of the breakdown of benzoyl peroxide).

It breaks down intercellular connections in the stratum corneum.

It can be used in the form of a 5% gel or 2.5-3% shampoo. Indications for its use include supplementing the treatment of superficial and purulent dermatitis, seborrheic disorders, especially those associated with the formation of comedones and follicular casts.

Benzoyl peroxide can whiten hair and items.

Benzalkonium chloride

It works by releasing atomic chlorine.

It shows strong bactericidal and fungicidal properties.

Chlorhexidine

It has antiseptic and disinfecting properties.

It works against many species of fungi, viruses, bacteria (except Pseudomonas and Serratia sticks).

Used in a concentration of 2-4%.

It rarely causes allergic reactions and is a perfect complement to the treatment of purulent inflammations of the skin.

It has a synergistic effect with EDTA, miconazole and phytosphingosine.

It has higher antimicrobial properties than benzoyl peroxide.

Ethyl lactate

Its antiseptic properties are achieved through the use of bacterial lipases of the skin flora.

They break down ethyl lactate into lactic acid and ethanol.

The resulting acidification of the skin creates conditions that are not conducive to the multiplication of pathogenic microorganisms.

Alcohol, in turn, dissolves excess sebum, making it easier to rinse off.

It also dissolves the sebum obstructing the hair follicles, thus facilitating the penetration of active substances into their interior.

So it has a bacteriostatic and anti-seborrhoeic effect.

Used in the treatment of purulent skin inflammations, especially bacterial folliculitis.

EDTA

Compound with bactericidal, disinfecting, alkalising and chelating properties.

It is used in the treatment of skin and external ear canal infections caused by Pseudomonas aeruginosa and other Gram bacteria-.

To intensify its antibacterial effect, it is combined with chlorhexidine and Tris (tromethamine).

The combination of Tris-EDTA shows a synergistic effect with enrofloxacin.

Keratolytic action

Salicylic acid

Thanks to its properties, which increase the binding of water by the diseased skin (thanks to which it is hydrated), it is used in the treatment of conditions with keratosis disorders.

It facilitates exfoliation of the epidermis, which is especially useful in the treatment of kerato-seborrheic conditions.

It works synergistically with sulfur, and such combinations are used in many anti-seborrheic shampoos.

Transretinoid acid

It has a strong keratolytic, anti-seborrhoeic and anti-acne effect.

Its use leads to the spontaneous elimination of blackheads, the transformation of microcysts into open comedones, as well as hindering the re-accumulation of sebum.

Selenium disulfide

It has keratolytic, anti-seborrheic, washing and antifungal properties.

It is used in the treatment of keratolytic conditions.

Keratoplastic action

Sulfur

It is an effective keratolytic agent, showing a synergistic effect with salicylic acid.

It has anti-seborrhoeic properties and also has the following properties:

anti-inflammatory,
decongestant,
antipruritic,
antiseptic,
antiparasitic.

The pitches

Coaltar - the oil fraction of coal tar and tar - wood tar are used in the local treatment of skin diseases.

They are characterized by various therapeutic effects:

keratomodulating,
antiseptic,
antipruritic,
painkillers,
astringent,
antiparasitic,
antifungal.

Their use is recommended in the treatment of keratolytic conditions.

Dog allergy

Allergies are an excessive, inadequate immune response or hypersensitivity of the body to substances naturally occurring in the environment or food, which are known as allergens or antigens.

Anything can be an allergen, but in dogs the most common hypersensitivity reactions are:

tree pollen,
grass pollen,
weed pollen,
mold spores,
dust mites,
different types of animal protein,
flea saliva.

Skin allergies in dogs often include:

itchy skin,
redness,
recurrent inflammation of the ears,
hair loss.

Very often, secondary bacterial or yeast infections develop on such a basis as allergic skin.

Simply put, it can be said that in dogs we most often deal with the following types of allergies:

flea allergy,
food alergy,
environmental allergy (atopy).

Flea allergy: flea allergy dermatitis

It is not actually an allergy to the flea as such, but rather to its saliva, in which numerous potentially allergenic substances are present.

At the time of feeding, the parasite introduces allergens contained in saliva into the epidermis and skin.

Their presence causes local inflammatory edema and migration of inflammatory cells to this place.

The immune system recognizes these substances as allergens and overreacts (this is called. hypersensitivity reaction), the effect of which is noticeable itching.

And indeed - the main symptoms noticed by the dog's guardian are intense itching and hair loss in places quite typical for this disease entity - this is it lumbosacral region up to the base of the tail.

In advanced states, the changes also apply to:

the rear surfaces of the thighs,
buttocks,
belly.

This condition is called flea allergic dermatitis (APZS).

A lot of controversy and doubts have developed around him, especially on the part of the keepers of the scratching dogs.

When flea dermatitis is suspected, many keepers vehemently deny the possibility of these parasites in a pet. Some people perceive similar suggestions as an affront, believing that their dog is clean and that the doctor's suspicions are at least out of place.

Another point is the belief that flea dermatitis is unlikely in the colder seasons.

The other most common argument is that the dog has never had fleas.

These and other doubts require immediate clarification.

First of all - the pet does not have to be flea, dirty and neglected for it to develop a disease.
Often, it is these very clean, sofa dogs, bathed and combed, that regularly exhibit symptoms of APZS. Even a short walk in a garden where fleas may be found amongst decaying organic debris is enough to catch the stowaway.
Secondly, fleas do not have to be visible with APZS.
In fact, one bite is enough for a dog to develop intense itching with subsequent changes in the skin.
Third, fleas can feed all year round.
In the warm months, the severity of infestation in animals increases, because then there are favorable conditions for the development of larvae and pupae in the external environment. However, in heated rooms, in the privacy of your home, fleas can develop throughout the year.
Not only that, they do not stay on their host all the time. Rather, they treat it as a furry, mobile canteen that they jump into from time to time.
They spend the rest of their lives hidden in crevices, carpets and lairs.
That is why flea prevention is recommended all year round. Firstly, to fight all live, active fleas that live on the animal, and secondly, to fight the next generations of fleas that hatch from the pupae (and these can survive in the environment even 3 months).
Fourth - it is sometimes extremely difficult to confirm the presence of fleas on the skin.
They may simply not be noticed, especially if the dog has a long and thick coat.

It is therefore possible that even a dog whose guardian did not notice the presence of parasites may develop severe itching, which is a manifestation of the disease.

The pathomechanism of flea allergy is complex. Type I hypersensitivity based on IgE antibodies, type IV hypersensitivity based on cellular responses and cutaneous basophilic hypersensitivity are involved.

There are several stages in the course of APZS in a dog

In the first stage, usually only severe itching is noticeable, with no other lesions.
The erythema on the skin is usually not very intense at this time. In short-haired dogs, reddish lumps may sometimes be observed on the skin.
When scratching, the dog may respond with reflex contractions of groups of skin muscles, and there may also be a scratching reflex.
In the second stage, other symptoms join the pruritus:
- skin hyperesthesia - the dog is extremely sensitive to touch in the area of the back,
- erythematous changes, especially at the base of the tail, in the lumbosacral region, on the inner and back surfaces of the thighs, on the abdomen, around the anus and the external genitalia.
In the third stage, self-damage occurs in the form of scratches and bites due to intense itching.
During this time, the immune reactivity tends to be the most intense.
Often during this period, secondary infection is added and acute, often exuding superficial dermatitis develops. There are pustules and scabs, in the affected areas there may be round or oval alopecia.
The chronic stage is rarely seen today.
As a result of a long-lasting disease, the skin may thicken and become thinning, with accompanying discoloration, as well as seborrhea and intensification of inflammatory changes.

The diagnosis of flea allergy dermatitis is made on the basis of fairness characteristic clinical symptoms and demonstrating the presence of fleas or their faeces on the animal.

Parasite excretions resemble very fine black grains that usually appear in clusters at the base of the hair or may be scattered throughout the hair.

A good method is to run a test with a damp tissue paper.

Using a dense comb or a brush, brush the dog in such a way that the fur and small particles taken from the hair during brushing fall on the white tissue paper moistened with water.

As fleas feed on blood, this test will reveal their faeces by creating a rusty brown stain on damp tissue paper.

Another test that can detect parasites is trichinoscopic examination or microscopic examination material taken with adhesive tape.

Treatment of flea allergy dermatitis should primarily be based on the control of fleas (both on the animal and in the external environment).

Flea prophylaxis should be carried out throughout the year, not only in summer.

There are many preparations on the market that are designed to combat these insects in animals. The most popular are those containing:

fipronil,
imidacloprid,
selamectin and others.

For allergy symptoms to subside, your dog must be completely flea-free.

In the case of secondary purulent infection, it is sometimes necessary to introduce antibiotics (local or general) for treatment, as well as the use of antiseptic and regenerating shampoos or other cosmetics to alleviate itching.

In the case of very intense scratching, treatment with glucocorticosteroids can be introduced, but usually an appropriate antiparasitic and antibacterial effect is sufficient to control the symptoms.

Atopic dermatitis

In veterinary offices, one of the most common reasons for consultation are:

allergic dermatitis,
otitis externa,
bacterial skin infections.

These three conditions are in many cases the clinical manifestation of the same underlying process:

atopic dermatitis.

The International Task Force on Canine Atopic Dermatitis (ITFCAD) has defined atopy as:

hereditary predisposition to the occurrence of allergic reactions due to contact with an antigen present in the environment.

In other words, there is some in atopic patients inborn tendency to overproduce IgE antibodies against various allergens.

Causes of atopy in a dog

The antigens responsible for the formation of atopy in dogs are similar to those that cause allergies in humans.

So pollen, molds, house dust mites, and storage mites can trigger an abnormal immune response in dogs.

Why is this happening? Here are some possible causes:

Various genetic and environmental factors can negatively affect the skin by damaging the epidermal barrier.
It has been shown that in atopic people the stratum corneum and other elements of the epidermis are different from those found in non-atopic people. It has been found that they occur in them defects in a key protein, responsible for the proper barrier function of the epidermis (protein is the so-called. filaggrin)and key lipids (ceramides).
In atopics, there are also disorders in the tightness of keratinocyte junctions, as well as abnormalities in their maturation, differentiation and exfoliation. All this means that the epidermis does not fulfill its basic function - the barrier becomes leaky.
This results in increased transepidermal water loss, deeper penetration of the lower layers of the skin by pathogens and increased colonization by bacteria (mainly Staphylococcus).
Environmental factors, such as proteolytic enzymes of house dust mites or exotoxins produced by Staphylococcus bacteria, further intensify the decomposition of ceramides, thus deepening the damage to the epidermal barrier.
Another element involved in the pathological response of the immune system and the development of atopy are
…
the immune mechanisms themselves. They play an important role in this process immunoglobulin E and mast cells, however, it is not as important as the role T lymphocytes.
T lymphocytes are cells involved in stimulating the immune response, and within them there are two important subpopulations: Th1 and Th2 lymphocytes. They are designed to produce a variety of cytokines in response to antigenic stimulation.
And yes Th1 lymphocytes on contact with the antigen, they produce cytokines that are involved in the antiviral response (interferons), antibacterial, antifungal and play an important role in wound healing and macrophage stimulation (IL-1, TNF-α), as well as stimulating the production of IgG antibodies by B lymphocytes.
Th2 lymphocytes in turn, they produce cytokines, which are mainly associated with the antiparasitic response by stimulating the release of eosinophils, increasing the expression of mast cells, releasing histamine and stimulating the production of IgE.
Th2 lymphocytes therefore stimulate the development of allergic reactions - it occurs in atopic dogs significant disproportion between Th1 and Th2 in favor of the latter, which results in the overproduction of eosinophils, mast cells and IgE antibodies.
Thirdly histamine.
She was once considered the main leader of itching. Indeed, histamine causes vasodilation, erythema and swelling, but in atopy it is not the only cause of persistent itching. If that were the case, antihistamines would be great at reducing itching in dogs, and the fact is that administration of this group of drugs is often disappointing.
Research into the neurological origin of allergic pruritus has revealed that there are several other major players involved in its pathogenesis: cytokines (e.g. IL-2, IL-4, IL-6, IL-13), among which the leader is interleukin 31 (Il-31).
It is a cytokine produced by Th2 lymphocytes in the epidermis in response to antigenic stimulation.
This bane, along with other cytokines produced by Th2 cells, brazenly binds to unmyelinated peripheral nerves, causing a real revolution in the brain.
The brain gets a clear signal: this is where it itches and says: you have to scratch!
This action is mediated by the JAK pathway, i.e. the group of the so-called. Janus kinases, which play a very important role in the course of, among others, immunological processes. This trail is there the most direct neuronal pruritus mediator.
Finally, Malassezia yeasts and Staphylococcus bacteria.
We all know that they love to complicate inflammatory processes in dogs. However, this is not the only nuisance they have in their arsenal.
It is now known that these organisms contribute to the development of atopic disease in dogs, and even are inherently associated with it.
The aforementioned epidermal barrier defects facilitate increased bacterial and yeast colonization.
Exotoxins produced by these microorganisms further break down lipids and continue to destroy the protective layer of the epidermis, aggravating the damage.
Antigens of yeast and bacteria additionally stimulate T lymphocytes, activating warning signals within the epidermis, leading to some hypersensitivity - now, after contact with environmental antigens (such as pollen, molds, house dust mites, etc.) this cooperation will cause these harmless proteins to be recognized by T cells as enemies.
So, future exposure to mites or trees will cause an abnormal over-response from the immune system. As a result, the skin disease gradually progresses from a healthy looking puppy, to a slightly scratching young dog, to dermatitis and itching all year round, and recurring bacterial and yeast infections in later years. That is atopic dermatitis in full bloom.

Symptoms of allergic dermatitis

One of the main manifestations atopy is allergic dermatitis, which it touches as many as 10% of dogs.

AZS manifests itself above all itching and skin changes, occurring in specific places of the body. They are mainly:

eye area,
lip area,
inner surface of the auricles,
ventral surface of the neck and abdomen,
circumferential sections of the limbs,
interdigital spaces.

Atopy is often accompanied by the presence of the so-called. post-itching changes that appear secondary to persistent scratching, licking or biting.

These are:

baldness,
abrasions,
discoloration of the coat,
in chronic conditions, discoloration of the skin and its thinning.

Reddening and papules are often seen on the skin.

The course of atopic dermatitis is often complicated by other dermatoses:

About half of the cases of atopy are associated with bilateral otitis externa. It happens that this is the only symptom of AD.
Often the disease can also be accompanied by both sides follicular conjunctivitis.
Frequent, recurrent inflammation of the skin caused by bacteria and / or yeasts.
Bilateral serous rhinitis (something like our hay fever) is also seen.

Diagnosis of atopic dermatitis in a dog

A detailed dermatological interview. There are special diagnostic criteria that can help diagnose AD in dogs. These are:
- the appearance of the first skin lesions before the age of 3. years of age (usually between the age of 6). month and 3. year);
- the dog being mostly at home;
- initially, itching alone, without skin changes (it may be permanent or intermittent);
- the presence of a syndrome in which atopic dermatitis is one of the causes, e.g. recurrent inflammation of the skin and / or external auditory canal, conjunctiva or nasal mucosa;
- the pruritus subsides after administration of glucocorticoids.
Characteristic clinical symptoms:
- inflammatory lesions of the skin on the peripheral parts of the breasts,
- changes on the inner surface of the auricles,
- no changes on the edges of the auricles and in the dorso-lumbar region,
- itching.
Exclusion of other causes of pruritus.
Treatment responses.

Serological allergy testing is not a method of diagnosing AD in dogs.

Screening tests that detect the total amount of IgE antibodies are unreliable.

Not every dog with AD has high IgE levels, and it also happens that a perfectly healthy dog, without any clinical symptoms of atopic dermatitis, has high IgE levels.

Therefore, they are still the gold standard in diagnostics intradermal tests.

These types of tests are designed to detect allergens causing symptoms of the disease in order to eliminate them (if possible) and / or to conduct specific immunotherapy.

How to deal with atopic dermatitis?

Managing atopic dermatitis is often a long and frustrating process for both caregivers and veterinarians.

This is not a condition where you only need to administer drugs and the animal will be cured after a certain period of time.

In fact, the therapy for each dog should be determined individually, taking into account:

the specifics of the disease,
clinical symptoms,
comorbidities,
response to treatment.

Currently, veterinarians use the following methods of treatment:

Symptomatic action (mainly aimed at reducing itching):
- Glucocorticoids:
  - Topical preparations, e.g. hydrocortisone aceponate - penetrates well into the skin, and a small amount into the blood, soothing itching.
    Its use allows to limit the dose of systemic drugs.
  - Oral glucocorticoids - administration is recommended prednisolone or prednisone at a dose of 0.5-1 mg / kg m.c. every 12-24 hours.
    As symptoms improve, the frequency of use is gradually reduced to the dose given every 48-72 hours.
    It should be remembered that steroid therapy is associated with the possibility of its occurrence numerous side effects, such as but not limited to: increased thirst, increased urination, weight gain, increased risk of skin infections. Therefore, during the entire therapy, it is necessary to control the patient's clinical condition, including monitoring of morphological and biochemical blood parameters.
  - The administration of long-acting or injectable corticosteroids should definitely be avoided.
- Antihistamines are administered more as an adjunct to steroid therapy to lower the doses of steroids.
- Cyclosporine at a dose of 5 mg / kg m.c. daily, after the symptoms have calmed down, the frequency of drug administration can be reduced (every 48-72 hours.).
  Cyclosporine works mainly by modulating the activity of T cells. Unfortunately, its administration may also be associated with the occurrence of side effects, the most common of which are gastrointestinal disorders (excessive salivation, vomiting, diarrhea), and long-term administration may lead to gingival hypertrophy.
- According to some studies, administration to dogs with AD is recombinant canine gamma interferon at a dose of 5,000-10,000 units / kg 3 times a week for a month and then once a week reduced itching.
  Feline interferon (Virbagen Omega), which is available on the market, can be administered at a dose of 1-5 million units 3 times a week for a month, and then once a month.
- The administration provides quick relief from intense itching, and in a way also the "causal" action oclacitinib (drug called Apoquel).
  Is it a very good alternative to glucocorticosteroids.
  Oclacitinib maleate is a selective inhibitor of Janus kinases. It selectively blocks JAK-1 kinase, which is present in the nerve ending receptors in the skin, stopping the neuronal stimulation of pruritus.
  During the first two weeks, the drug is administered at a dose of 0.4-0.6 mg / kg.c. every 12 hours, and then reducing the frequency to once a day.
- N-palmitoeiletanolamide (known as hydroxyethylpalmitamide - PEA or Palmitamide MEA) is a substance that acts on CB1 / CB2 cannabinoid receptors (found naturally in the skin of humans and animals), inhibiting the synthesis of pro-inflammatory cytokines (IL-4, IL-6, IL-8).
  By its action, it soothes itching of the skin and reduces its congestion, it also inhibits the development of free radicals responsible for skin aging. The preparation available on the Polish market is Redonyl Ultra.
- Therapy with monoclonal antibodies, cloned from a single B cell line.
  One such canine monoclonal antibody is Lokivetmab (prep. Cytopoint). It blocks interleukin 31 (the serious gamer that sends itching signals to the brain) by preventing it from attaching to a coreceptor.
  Interestingly, its antipruritic effect begins within a day after subcutaneous administration, and the effect lasts for 4-8 weeks.
Supportive treatment
- Introduction of specific antigenic immunotherapy (i.e. popular desensitization).
  Allergy tests should be carried out as soon as we know where our diagnosis is going. Antigen-specific immunotherapy supports the subpopulation of T lymphocytes - the so-called. regulatory T lymphocytes (formerly known as suppressor lymphocytes).
  This group of lymphocytes is responsible for suppressing an overly increased immune response by restoring the balance between Th1 and Th2.
  Thanks desensitization is braked, among others.in. synthesis of IgE antibodies, increase of IgG, decreased production of pro-inflammatory cytokines by mast cells, eosinophils and T lymphocytes.
  In practice, allergic animals are regularly given the appropriate allergens (determined in advance by allergy tests) in incremental doses and then in maintenance doses. The goal is to develop tolerance to the applied allergens.
- Polyunsaturated fatty acids, both in the form of supplements and topically on the skin.
  EFAs administered with steroid therapy support treatment and often allow the dose of glucocorticosteroids to be reduced. In the form of topical applications, they help seal the epidermal barrier and relieve itching.
- In addition to pharmacology and care, it is also necessary to identify and - if possible - eliminate any allergens that sensitize our dog. In many cases, unfortunately, it is not possible to completely exclude all allergens, but even their reduction may bring noticeable clinical results in the form of relief of itching and withdrawal of the symptoms of skin inflammation.
  The procedures may take the form of:
  - Application of an elimination diet with a provocation test.
    Unfortunately, allergies often come in pairs, threes and even in larger clusters. It happens that the unequal fight against atopy and mediocre treatment results are due to the fact that it is not the only "allergic" culprit of itching.
    In such situations, even the best planned and conducted treatment of atopy will be of no avail if it is accompanied, for example, by. food alergy.
  - Flea prophylaxis and control of the presence of parasites in the places where the dog is.
  - Performing intradermal and / or serological tests.
  - Fight against dust mites, mold spores and other allergens where your dog is.
  - Antibacterial and antifungal treatment.
skin care.
- Great attention should be paid to the functioning of the epidermal barrier, as its defect contributes to the development of the disease.
  Consistent use of topical moisturizing and oiling agents (emollients) greatly reduces the progression of atopy in young dogs and helps repair damaged skin in elderly patients with atopy.
- Therapeutic baths for allergic dogs cannot be overestimated. Especially that most of the shampoos on the market support the regeneration of the epidermal barrier through the content of m.in. phytosphingosines and ceramides. Addition chlorhexidine reduces the amount of bacteria and yeast on the surface of the skin, which not only helps to fight active infection, but also prevents it from reoccurring.
  Using cosmetics containing chlorhexidine at least once a week can reduce the severity and frequency of future skin infections.
Early recognition and rapid intervention to alleviate the course of atopy as well as prevent bacterial and fungal infections.

Food alergy

Adverse Food Reaction. Adverse Food Reaction AFR) are any clinical abnormalities found in a patient that are related to the consumption of a food product.

It is an umbrella term that covers all symptoms and syndromes related to food, including skin, respiratory and digestive reactions, neurological symptoms and hematological disorders.

It is also included in this broad group of various clinical conditions induced by the consumption of a particular food food allergy in a dog.

The term is often used interchangeably with food intolerance, which is not entirely true.

Let's see how these bands differ.

What is a food allergy in a dog?

Food allergy is a true hypersensitivity reaction, consisting in an immune reaction in response to the ingestion of an antigen in the form of a specific ingredient (most often a protein).

What is a food intolerance in a dog?

Food intolerance (also known as food indigestion or food poisoning) is an abnormal reaction of the body to food, food additives, or contaminants present in food, which is not accompanied by a response from the immune system.

E.g. after eating stale fish, vomiting is not a symptom of food allergy, but food intolerance.

Diet-related dermatitis is any skin disease that results from your diet.

Another term used interchangeably is "Cutaneous Adverse Food Reaction" (CAFR).

Thus, dermatitis may be due to either an allergy or an intolerance.

Food alergy can develop at any age - both in very young dogs (less than 1 year old). years of age) and mature ones (allergies have been reported even in 14-year-olds who have never pruritized before).

Most often, however, the symptoms of food allergy in a dog show up between 6. month and 4. year of life.

The process of sensitizing the animal to a given nutrient may continue 2 months or more - more than half of the dogs are fed a given protein for a period of approximately 2 years before showing clinical signs.

The disease is non-seasonal in nature, that is, the appearance of clinical symptoms or exacerbations at certain times of the year is not observed.

It is difficult to determine the prevalence of food allergies in dogs, but it is safe to say that at approx. Food is the trigger in 10-15% of scratching patients.

The most common antigens that trigger an allergic reaction are high molecular weight proteins, which are typical ingredients of most commercial pet foods, but also home-made diets.

The typical size of protein is 10-60 kilodaltons.

They can also be allergens glycoproteins, and even carbohydrates.

The most common food allergen is chicken, and right behind him beef. Other allergens include:

lamb,
pork,
dairy,
horseflesh,
eggs,
wheat,
oat,
fish,
corn,
corn starch.

Increasingly, allergies to:

rice,
potatoes,
venison,
the duck.

Even a minimal amount of a given ingredient can cause serious clinical reactions, completely disproportionate to the amount taken.

But not only the type of protein influences the occurrence and severity of an allergic reaction. Other factors that may affect food allergy include:

quantity,
digestibility,
manufacturing technique,
presence or absence of heat treatment (cooked versus raw).

Symptoms of food allergy in a dog

Food allergy should be suspected in any patient with prolonged pruritus, recurrent ear inflammation, dermatitis, recurrent pyoderma (pyoderma), or malasiosis.

On the basis of clinical symptoms alone, it is impossible to distinguish food allergy from atopy. Both states are accompanied by:

Localized or generalized itching - in some patients skin changes and itching affect the ears, feet, inguinal and axillary areas, the dorsal surface of the forelimbs, the muzzle and the skin around the eyes.
Other dogs, on the other hand, show only ear inflammation, and other parts of the body show no skin lesions.
Primary eruptions are most often erythema, papules, erosions and ulcerations.
Less common is urticaria, angioedema or perianal fistula.
Secondary lesions include hair loss, hair loss, scales, crusts, discoloration (hyperpigmentation), skin thinning, and pustules associated with secondary bacterial or yeast infection.

Unfortunately, these symptoms are very non-specific.

Food allergy cannot be diagnosed on the basis of the information obtained from the caregiver and the image of the lesions. However, there are some indications that clearly suggest a food allergy background. These are:

Itching that is unrelated to the season of the year.
Pruritus is poorly amenable to steroid therapy.
The pruritus is accompanied by gastrointestinal symptoms, e.g. fluctuating appetite, persistent yawning, gas, unreasonable episodes of vomiting or diarrhea.
There are reliable indications and observations that any change in diet or exposure to a given nutrient exacerbates itching or gastrointestinal symptoms.

If, on the basis of the information obtained, a suspicion of food allergy occurs, the surest way to confirm it is to conduct an elimination diet with a subsequent provocation attempt.

Elimination diet when food allergy is suspected

In practice, introducing an elimination diet is difficult, frustrating and often met with considerable resistance from dog handlers.

And introducing such a diet is advisable not only in the case of chronic itching, but also in the case of frequent, recurrent purulent inflammations of the skin or even otitis externa.

It is difficult to conduct a successful elimination test.

Often even more difficult than persuading the caretakers to follow it.

The most common obstacle is continual exposure to nutrients other than those contained in the test diet.

And it is worth doing as it is a very important diagnostic test for the evaluation of patients with itching, pyoderma and / or inflammation of the outer ear.

Carrying out an elimination diet is a multi-stage process.

As I have already mentioned, many dog handlers approach her with a strong reserve, which is fully justified.

In fact - it is quite a long job, requiring constant concentration and attention, regularity and letting go of compassion for a period of about 8 weeks.

But worth.

First, because we are getting closer to the truth every day.
A correctly conducted test will show us which diagnostic and therapeutic path to take.
Second - if I had to choose between food and environmental allergies, I would definitely choose the former.
Here I have control over what I give my dog, I can really help him by eliminating all allergenic ingredients from the food.
In the case of grass pollen, unfortunately I do not have such competences.

The elimination diet consists in feeding a suspected animal for several weeks with mono-foods that have not been eaten so far.

Before starting the diet, it is a good idea to establish a starting point, a baseline of the current level of itching, against which we will judge our dog.

We evaluate - on a scale of 1 to 10, where 10 is the worst, most intense itching that the pet has ever experienced.

It is worth creating a notebook in which we will write down information about the severity of itching, but also other observations, such as:

redness and swelling of the ears,
unpleasant smell,
shaking your head,
wallow,
rubbing,
reduction of itching (e.g. improvement of the condition - from generalized itching to licking, e.g. only paws).

This and any other information should be entered in the notebook once a week.

What kind of food should be used to carry out an elimination diet?

There are 3 options to choose from:

Home-cooked diet, based on 1 type of new protein, 1 type of carbohydrate and 1 type of fat.
It is important that the served products are not raw, but heat-treated (e.g. cooking or baking). Such homemade food is considered to be the optimal method of eliminating all suspicious ingredients.
You have total control over what you feed your dog because you are the one who prepares the meals at home. In addition, some pets respond more rapidly to their clinical condition on a cooked diet.
An example diet prepared at home is based on a 1: 1, 1: 2 or 1: 3 ratio of protein and carbohydrates plus a tablespoon of oil.
A good source of protein can be pinto beans, rabbit.
Should be avoided pheasant, ducks, turkey, eggs, fish, venison, lamb.
Cross-reaction with the muscle proteins of other animal species may occur.
These foods can be given later on during a maintenance diet, but they are not good for a test diet.
They are good carbohydrates sweet potatoes, pumpkin, quinoa. Consider including it in your diet potatoes or sweet potatoes.
Preferred oils are walnut oil, sunflower seeds or oil.
However, such a nutrition may not be nutritionally complete as regards long-term administration. Additionally, preparation is time consuming and the high fiber content can impressively increase the number of bowel movements.
Therefore, always with long-term administration of elimination food, prepared at home, it is necessary to consult a veterinary nutritionist in order to optimally balance the nutrition with minerals, vitamins and other necessary nutrients.
Commercial diet, containing a different type of protein than what your dog has been eating before.
The age of caregivers chooses this method of eliminating a potential allergen from food, because these foods are more convenient to use (it is enough to buy them in a store).
The concept of a diet with new white is based on the fact that the dog cannot be allergic to a protein that has never been exposed to it before.
In reality, however, there may be some kind of cross-reaction between different meat sources. It may happen, for example. so that a dog allergic to beef will also react to the meat of other ruminants, and a patient allergic to chicken will react to food with duck or turkey, which are common ingredients in commercial foods.
So there is no one single food that is 100% effective in diagnosing food allergic dogs. Multiple dietary trials may be required for a complete evaluation.
Therefore, it is advisable to stick to a type of protein that is not found in common diets and is not closely related to beef, chicken and fish. So meat seems to be safe rabbit.
Other new types of proteins can of course be introduced during a maintenance diet when we have an empirically proven lack of response to these ingredients. However, when we are introducing an elimination diet to determine if our dog has a food allergy, our goal is to perform it as perfectly as possible.
Unfortunately, sometimes despite a perfectly made selection in the selection of commercial pet food, other factors - independent of us - interfere with our plans.
It is about something as prosaic as how to make food for animals. Food producers usually offer many types of food with various compositions.
Unfortunately - they are usually produced in the same factory, and often even on the same production line as other feeds, so there is a risk that the purchased feed will contain (unintentionally!) additives of other proteins, including those that sensitize the dog.
This type of diet is therefore very risky, as your pet may continue to scratch, confusing both you and your doctor. Because he doesn't get allergic chicken or beef, right?
The second aspect is that your pet may be allergic to more than one ingredient - it may be 2, 3 or even 10 types of allergens.
Therefore, most veterinary dermatologists suggest introducing diets with a limited number of potential allergens, i.e. from only one type of protein and one type of carbohydrate.
A specialized diet made of hydrolyzed protein.
The idea behind such a diet is that in order to stimulate the immune system, the protein should have a specific molecular weight, much lower than the one that sensitizes.
It's still unclear how small a protein molecule must be in order not to trigger an immune response in an allergic dog. It is assumed that its size should be around 1 kD. So if a protein molecule is split into smaller particles, the immune system will not recognize it as allergenic and will not stimulate unwanted reactions.
In theory it looks really great, but there are times when some dogs still react with this diet and their clinical symptoms worsen. Nevertheless, this diet can be a really good alternative to home-cooked food.

There are a few important things to keep in mind during an elimination diet that lasts 8-12 weeks:

This diet does not cure itching miraculously.
It is not the rabbit's protein that the dog does not scratch, it is only the effect of eliminating harmful proteins.
Since it is not known which protein is causing the symptoms, we must avoid all suspects.
We do not expect complete resolution of clinical symptoms. In fact, there may not be any changes at all by 4-6 weeks.
Even a small response to diet is still the answer. Do not be discouraged, as it may be caused by other factors, such as:
- atopy,
- fleas,
- pyoderma, etc.
It is absolutely forbidden to give your dog any treats previously used.
The application of certain medications (especially those containing flavorings) and supplements must also be stopped.
We only serve the selected food, without diversifying it with anything else.

A provocation attempt

The most important part of this study is provocation attempt.

After all, there is always a suspicion that the improvement seen during an elimination diet may be more related to the administration of drugs, getting rid of parasites, elimination of infections or even a change in contact and exposure to environmental allergens.

So how can we be sure that it is food allergens, and not comprehensive treatment, that contributed to the improvement of the condition of our fur??

There is a simple way to do this. Let's provoke an allergy!

If, after introducing the original diet, with all favorite delicacies, teethers and supplements, we observe an increase in itching and the reappearance of known clinical symptoms, we have confirmation.

This is especially true when the elimination diet has not substantially improved your dog's condition.

Maybe the handler has noticed a slight reduction in infection and ear odor, the redness may not be as strong as before, but the dog is still licking his paws, so this diet does not help at all.

And here we enter with a whole arsenal of allergens contained in our pet's diet, which, after eating, evidently increased clinical symptoms to the level observed before the nutritional challenge.

Changes during the diet can be slight, subtle. And the real determinant is a provocation attempt.

The provocation should be carried out gradually.

By 5 consecutive days we mix the elimination diet with the original one so that it is present in the bowl 3/4 of the test diet, 1/4 of the original diet plus what the pooch usually ate (i.e. snacks and supplements).

Watch carefully to see if there has been any change from the last observation in the notebook.
Check that the indicator on the Itch Scale has moved.
If pruritus and other dermatological symptoms worsen, do not continue with challenge. Stop it and go back to the test diet.

This flare-up shouldn't be long - it will probably take 5-15 days for pruritus to return to baseline.

However, you should always keep a close eye on the animal.

Especially in patients with severe clinical symptoms (such as convulsions, perianal fistula), the introduction of a provocation test may be a serious burden.

Returning to the test diet will resolve these symptoms.

If, on the other hand, after 5 days of feeding the dog with provocative food, the dog's symptoms have not worsened, it is most likely not a food allergy. Further diagnosis should be made, focusing on other causes of itching.

All right. But is it really necessary to provoke the onset of symptoms?

If the pruritus has subsided and the dog is finally sleeping soundly, I must give him a recurrence of all these unpleasant sensations??

These are some of the questions dog handlers ask after 8 or 12 weeks of an elimination diet.

Some of them don't even ask at all, they just refuse to introduce a provocation attempt.

They do not want to trigger symptoms, claiming that everything is fine, and the dog stays on such a diet for the rest of his life.

This is not the best approach.

The provocation is very important to make sure we are dealing with a food allergy, because yes, we still don't know.

That the symptoms have subsided may unfortunately only be a coincidence.

This is often the case with environmental allergies. For example, the dog developed itching for the first time in May.

After 3 months of worsening symptoms, an elimination diet for 12 weeks was introduced.
After this time, the symptoms completely resolved, but the caregivers did not conduct a provocation test.
The dog did not scratch himself until it got warmer (late March) and the keepers started taking him for longer walks to the park.

Relief of clinical symptoms may therefore have nothing to do with the diet, but with the lack of flowering of the plants to which the dog may be allergic.

Or maybe the pet in the park was eating some snacks after all?

Unfortunately - due to the lack of a provocative attempt, they were deprived of the chance to come to the truth.

After the provocation test, we already know that the dog is allergic to some food ingredient.

I don't know what ingredient it is, or if the allergy is triggered by more proteins.

Some dogs are allergic to one type of dog, others to 2, and still others to more types of allergens.

The only effective treatment for food allergy is avoiding all allergenic proteins. Therefore, further treatment can go two ways: either the owners will continue to give the test food until the end of the pet's life, or they will try to determine what specific allergens trigger the response in their pet in order to avoid only these ingredients and diversify the diet.

The search for an allergenic component can be as follows:

After the provocation diet is over, we revert to the test diet for a period 2 weeks. The goal is to restore your baseline and soothe any symptoms associated with allergen stimulation.
We choose one (and only one) most likely nutritional ingredient that may sensitize our client. It can be beef, chicken breast or corn.
We add 1 tablespoon (no more) of the suspect ingredient to each dog's meal.
We do this for 5 days, carefully observing any symptoms of exacerbation of itching.
If allergy symptoms develop, we stop the sensitizing protein immediately and go back to the test diet for a full 2 weeks before deciding to add another protein from the list of suspect ingredients.
If, on the other hand, the pet's condition does not deteriorate within 5 days, we also discontinue the provocative protein and return to the test diet.
Although the pooch is not allergic, we do not give this ingredient yet. We wait 2-5 days and introduce another protein.

The described method of conducting a provocation test is quite controversial. Because can't you shorten the entire diagnostic path and, after completing the elimination diet, introduce one selected, and the most suspect, nutrient??

Of course you can, and it is one of the ways of provocation.

It works best in dogs that have significantly improved their clinical condition and have reduced, or even completely regressed, clinical signs of allergy and pruritus.

Then a really food allergy is very likely and you can concentrate on searching for particular, allergenic food components.

It is done like this:

A single, potentially sensitizing product from the previous diet is introduced into the dog's nutrition for a period of about 14 days.
During this time, nothing else changes - we only add one element of the diet.
During the challenge, we observe the animal and record the observations. If the pruritus or other symptoms are exacerbated, discontinue the sensitizing product immediately and return to the test diet.
This should be done with any type of suspect carbohydrate or protein. The duration of such an investigation varies in length, and depends largely on how varied the diet was, causing the symptoms of allergy.

Are there any easier alternatives to an elimination diet?

Diagnostic tests have been developed that have the potential to detect food allergy in animals.

These are intradermal tests, serological tests, and even endoscopic tests (sprinkling of antigen extract on the gastric mucosa).

However, an elimination diet and the subsequent challenge test remain the most reliable tool in the diagnosis of food allergy in dogs.

Dog intradermal allergy tests

Dog intradermal allergy tests involve injecting specific extracts of food protein into the skin and observing the formation of a bubble on its surface. The goal is to trigger a specific allergic reaction in the form of mast cell degranulation.

Unfortunately, mast cells may have nothing to do with the manifestation of adverse reactions to food.

One study found a very weak correlation with proteins that triggered a response when administered to a patient provocatively in food.

Dog serological tests

Serological tests measure the level of IgE antibodies specific for allergens by means of an ELISA test.

Unfortunately, IgE may be poorly involved in the pathogenesis of adverse food reactions.

Therefore, this test may show poor correlation with the dog's specific sensitiser protein that has been provocatively tested. In other words - blood tests are in many cases not reliable enough.

There are hopes for the use of epidermal patch tests (known from human medicine).

In these tests, a suspension of powdered dog food or a specific ingredient is suspended in a neutral lanolin base, placed on a petal in special chambers (facilitating the application of the allergen and ensuring perfect contact with the epidermis) and glued to shaved skin for 48 hours.

After this time, the flap is removed and the skin lesions are assessed for erythema and skin tightness for each component tested.

Treatment of food allergy in a dog

Treatment of food allergy should be based on the elimination of those components from the diet that cause hypersensitivity reactions.

There is no other way.

The diet should be selected so that it is well tolerated by the dog, and at the same time it can be used for a long time without harm to the body.

In addition to excluding trophoallergens, it must also be properly balanced in terms of nutrition.

For this purpose, I always recommend contacting a veterinary nutritionist who will help in determining the proper nutrition of the dog.

You should also regularly examine the faeces in order to detect and eliminate possible worming.

Intestinal parasites, which are responsible for the inflammation of the gastrointestinal mucosa, thus increase the risk of allergy to another nutrient.

It is also extremely important to prevent the recurrence of secondary infections and seborrheic dermatitis, as well as the maximum protection against fleas.

Infections

Purulent dermatitis

Pyoderma, i.e. purulent, bacterial skin infection is a very common motive for dermatological consultations, second only to flea allergic dermatitis.

Dogs appear to be more prone to bacterial skin infections than other domestic animals or even humans.

This may be due to differences in the epidermal barrier:

higher pH,
weaker passive immunity in the form of lipids and antibacterial peptides,
thin, dense stratum corneum, etc.

Additionally, dogs may have an increased incidence of underlying diseases that predispose them to excessive bacterial growth.

However, the vast majority of pyoderma are complications of an underlying disease, such as.:

atopic dermatitis,
food allergy,
flea allergy dermatitis,
demodicosis,
Cushing's syndrome,
hypothyroidism,
autoimmune diseases,
diseases associated with keratosis disorders.

Regardless of the cause, however, pyoderma very often causes significant discomfort in dogs and frustration for their owners, caused by frequent relapses or failure to respond to treatment.

According to literature reports only over a dozen percent cases are primary pyoderma, in which the implementation of an appropriate antibiotic results in the complete elimination of the disease.

The causes of purulent dermatitis

The most common culprits of purulent skin inflammations are Staphylococcus pseudointermedius (the former name of the staphylococcus S. intermedius renamed).

This group of bacteria is a normal resident, residing on the surface of the skin and mucous membranes in dogs, and most abundantly in the mouth, nose and anus area, but these staphylococci act as an opportunistic pathogen.

As a result of changes in the microenvironment, favoring excessive colonization by opportunistic bacterial strains, their significant multiplication occurs.

This is known as bacterial overgrowth syndrome.

The factors that promote the formation of these changes are the previously mentioned underlying diseases, and due to the fact that in most cases they are chronic diseases, there are frequent re-colonization of staphylococci, which result in the re-development of purulent inflammations of the skin ( even after successful treatment).

This state is recognized on the basis of:

chronic, recurrent pyoderma,
the presence of epidermal colonies,
pustular pyoderma,
foul-smelling seborrhea,
dermatitis of the folds associated with friction
bacterial folliculitis.

Treatment of purulent inflammations of the skin can sometimes be problematic.

Overall, Staphylococcus pseudointermedius strains were sensitive to:

cephalosporins,
amoxicillin with clavulanic acid,
semi-synthetic penicillins and many other groups of antibiotics.

However, in recent decades there has been an increase in methicillin-resistant strains of staphylococci, which causes significant problems in the successful treatment of infection.

There are also other methicillin-resistant staphylococci, e.g. Staphylococcus aureus.

However, while infections with the latter only occurred after contact with a vector or a contaminated environment, Staphylococcus pseudintermedius is probably capable of infecting susceptible dogs even without an identified vector.

This is dangerous because he can become a normal resident on dogs. As a result, transmission of the pathogen from both other dogs, humans and even the environment to a susceptible dog can be greatly facilitated.

Currently, MRSP - methicillin-resistant strains of staphylococcus (. methicyllin-resistant Staphylococcus pseudointermedius) have become a common isolate from dogs with staphylococcal pyoderma.

The matter is further complicated by the fact that they are not only resistant to β-lactam antibiotics, but may also be resistant to other groups of antibiotics commonly used in veterinary medicine, including:

fluoroquinolones,
macrolides,
sulfonamides,
tetracyclines.

As a result, there is a need to reach for less desirable antibiotics, such as:

chloramphenicol,
rifampicin,
aminoglycosides.

What are the reasons for this?

One of the most critical factors in developing antibiotic resistance is earlier use of antibiotics (unfortunately sometimes ill-considered and unjustified).

Other bacteria found in purulent skin infections include:

Staphylococcus schleiferi and Staphylococcus aureus - these staphylococci also have a high probability of multi-drug resistance.
Staphylococcus epidermidis and S. xylosus are less frequently isolated and may accompany S. pseudointermedius.
Gram-negative bacteria: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Enterobacter.
Pseudomonas aeruginosa (blue oil rod) is often associated with mixed infections.
The primary etiological factor accounts for 30% of cases.
Atypical Bacteria:
- Actinomyces,
- Nocardia,
- Mycobacterium.

Classification of purulent dermatitis

The classification of pyoderma can be carried out based on a variety of diagnostic criteria.

Below are some of the most commonly used classifications for pyoderma in dogs.

Classification of pyoderma depending on the cause:

Primary pyoderma - occurs on healthy skin as a primary disease, and one type of bacteria is usually isolated from skin lesions.
Secondary pyoderma - it may be clinically identical to the primary pyoderma, however, a different disease process is always found earlier (e.g. atopy).
More than one type of bacteria is usually isolated from purulent lesions.

Pyoderma classification based on the depth of the inflammatory process.

This division takes into account the extent to which the purulent inflammatory process covers individual layers of the skin.

Superficial pyoderma covers the outermost layer of the epidermis. This group includes:
- acute oozing dermatitis (popular "hot spot in dogs "),
- multi-fold superficial dermatitis (also known as. purulent eruptions, also known as intertrigo)
Superficial pyoderma covers the epidermis along with the mouth of the hair follicle. Here are:
- superficial pustular dermatitis (the so-called. impetigo),
- superficial purulent inflammation of the proximal part of the hair follicle (the so-called. superficial folliculitis)
- superficial expanding pyoderma.

Superficial and superficial pyoderma include the epidermis, not reaching the basal layer.

They are exudative and the characteristic changes observed in their course are epidermal collar spots, papules, submerged pustules, scales (dry) and crusts.

It accompanies these pyodermas very often itching.

Deep purulent inflammation covers all layers of the skin, reaching down to the dermis and even the subcutaneous tissue.

The changes that accompany them are nodules, ulcers and fistulas with purulent exudation, and crusts.

The skin in these conditions hurts more than itches.

This group includes:

generalized deep purulent inflammation of the distal hair follicle and furunculosis (generalized folliculitis / furunculosis).
A common example is the pyoderma of German Shepherds.
Local deep purulent distal folliculitis and localized folliculitis / furunculosis, e.g.:
- purulent inflammation of the interdigital spaces (the so-called. pododermatitis),
- purulent inflammation of the nose of the nose,
- purulent calluses,
- canine acne,
- acute oozing dermatitis with furunculosis.
Cellulitis.

Classification of pyoderma based on the clinical appearance of the lesions:

Seborrheic pyoderma with erythema, erosions and exudation. This group includes:
- Bacterial overgrowth syndrome, accompanied by itching and an unpleasant smell.
  Erythema, scales, seborrheic effusion are most often located on the skin of the abdomen, interdigital spaces and the inner surface of the auricles.
  The most common bacterial growth occurs on an allergic or hormonal background. Treatment is mainly based on local action.
- Purulent erosions, otherwise intertrigo.
  Here, the skin lesions mainly involve folded skin. This is because there are specific conditions in places such as the muzzle of short-nosed breeds, the tail folds of bulldogs, the labia folds of obese bitches, or of shar-peas all over the body - there are specific conditions - most often lack of air supply and frequent irritation. The skin on the folds is usually moist, possibly exuding, oily, with erythema present.
  The procedure is based primarily on local therapy.
Papules, pustules, peeling, local alopecia.
Purulent dermatitis, which is manifested by such changes, includes:
- Impetigo (impetigo), referred to as purulent dermatitis in puppies (occurs mainly in young dogs, especially neglected). The typical clinical changes are epidermal rims.
  Older dogs that are immunocompromised may develop similar lesions with large pustules - this is called. bullous lichen.
- Bacterial folliculitis.
  It is the most commonly diagnosed pyoderma. Symptoms are small erythematous papules, spots, pustules, epidermal rims, associated with hair follicles.
- Extending superficial pyoderma.
  In its course, large epidermal rims appear on the skin, widening, erythema and peeling, there may also be exudate.
  Treatment initially involves local therapy, if it is ineffective, general antibiotics are introduced.
Erosions and / or ulcers:
- Purulent traumatic dermatitis (acute oozing dermatitis) - infection is accompanied by severe exudation and very severe itching, and even pain. It is the result of repeated skin damage, e.g. due to severe itching with skin allergy.
  Local treatment of oozing lesions and erosions is recommended. If you develop bacterial folliculitis and a deep boil, with alopecia, erosions, and ulcers, you may need to the introduction of systemic antibiotics.
- Purulent eruptions.
- Purulent inflammation of the skin of the mucosal joints.
  At the border of the skin and mucous membranes (e.g. around the lips, anus, vulva or foreskin), erosions and scabs are formed. Quite often, this phlegmon is diagnosed in German Shepherds.
Ulcers and fistulas.
These types of changes are typical in the course of rectal furunculosis (a disease that often affects German Shepherds).
They are accompanied by fetid, serous, purulent or purulent exudate. General symptoms include frequent and painful urge to stool, painful defecation, diarrhea, constipation, sometimes apathy and weight loss.
Lumps and regional swellings.
An example would be juvenile cellulitis.
The disease is most common in puppies to 4. month of life.
Caregivers observe a sudden onset of facial swelling, mainly around the lips, eyelids, nose and auricles. Pimples, papules, vesicles and erythema appear all over the head very quickly. Sometimes the changes affect the foreskin, vulva and anus area. Flagging subcutaneous nodules are present on the trunk.
The disease is accompanied by general symptoms:
- sadness,
- lack of appetite,
- fever,
- enlargement of the lymph nodes.

Classification of pyoderma based on location:

pyoderma of the folds around the lips, face, tail, vulva (intertrigo),
pyoderma that occurs in areas of friction (armpits, groins),
pyoderma involving the trunk - generalized,
subodermatitis / pyoderma of the interdigital spaces,
purulent inflammation of the external auditory canal.

Classification of pyoderma based on clinical effects:

Simple pyoderma.
Pyoderma heals and does not reappear. The disease occurs as a result of bacterial overgrowth or infection caused by microorganisms normally residing on the skin or opportunistic. With such conditions, there is usually no significant underlying disease.
Pyoderma reacts quickly to local antiseptics (e.g. dog shampoos with chlorhexidine) or systemic antibiotics (cephalosporin for 3 weeks).
The disease is not recurrent (there is a low probability that it will repeat itself), and it is not burdensome for the caregiver. Examples:
- impetigo (puppy pyoderma) - transient, pustular pyoderma, usually self-limiting,
- folliculitis, secondary to poor hair care (matted hair, presence of tangles),
- external parasites.
Recurrent chronic pyoderma.
The disease resolves with long periods between relapses, but often comes back. It is the result of re-colonization by resident bacteria (Staphylococcus), rather than treatment failure (failure to eliminate infection). The interval between disease episodes is usually longer than 2 weeks. Conversely, if pyoderma occurs less than a week after stopping treatment, it is most likely a treatment failure (and not bacterial re-colonization).
Chronic pyoderma and recurrent pyoderma are almost always the result of an ongoing underlying disease, e.g.:
- non-parasitic allergic dermatitis (atopy, food allergy, contact allergy),
- hypersensitivity to parasites: fleas, Cheyletiella, scabies,
- primary parasites (Demodex),
- endocrine diseases (hypothyroidism, hyperadrenocorticism),
- hair follicle disorders:
  - blackheads (schnauzers, hairless breeds),
  - follicular dysplasia (Dobermans, other black-haired breeds),
  - inflammation of the sebaceous glands (poodles, Akita, samoyeds),
  - immunodeficiency (true immunodeficiency is very rare),
  - hypersensitivity to staphylococci.
Treatment failure.
No response to treatment, no cure or relapse in less than 7 days after the end of treatment.
Why treatment may be ineffective? Here are the most common causes:
- The caregiver's failure to follow the instructions, especially regarding the administration and proper dosage of the antibiotic.
  It is even a more common cause of treatment failure than bacterial resistance to an antibiotic itself.
  One human study found that up to 60% of prescriptions have never been filled, and of those realized only 40% of drugs are properly dosed, at the prescribed time and at the times of the day specified by the doctor.
  If the dog does not want to take the pills, or if side effects occur, such as. diarrhea, vomiting - your pet will not be given the medicine by your caregiver.
  Also, if you need to administer your medication several times a day, you are more likely to miss a dose.
  Giving an antibiotic once a day is more accepted by both the handler and his dog.
- The wrong antibiotic.
  Antibiotics should be selected primarily on the basis of effectiveness (assessed with an antibiotic profile), convenience of feeding and prices (in that order).
  Unfortunately, antibiotics are often selected empirically, and only then no treatment effects the doctor's syntax to perform an antibiotic scan.
- Insufficient dose or incorrect dosing interval.
- Inadequate duration of antibiotic therapy.
  Often, animal keepers stop administering the antibiotic as soon as clinical symptoms have subsided or when adverse reactions develop (decreased appetite, vomiting or diarrhea).
  In general, pyoderma should be treated a minimum of one week longer from the time all clinical symptoms have disappeared.
- There is resistance to the antibiotic.
- Incorrect diagnosis and therefore incorrect treatment.
  Similar clinical symptoms may also occur in other diseases. Failure to respond to treatment should prompt the physician to reconsider the disease entities on the differential diagnosis list.
  These are among others:
  - demodicosis (demodicosis),
  - dermatophytosis (mycosis),
  - pemphigus deciduous (autoimmune disease),
  - Malassezia dermatitis,
  - T-cell lymphoma,
  - skin drug rash, erythema multiforme,
  - sun damage to the skin.
- Other factors:
  - Low concentration of antibiotics in the target tissue.
    The skin only receives 4% of the total cardiac output, for comparison:
    - muscle tissue 33%,
    - kidneys 25%.
  - Immunodeficiency.
  - Failure to recognize and treat underlying diseases (e.g. atopy).

Symptoms of purulent inflammations of the dog's skin

Pyoderma can take a different clinical picture depending on the form of the disease.

Depending on the depth of the inflammatory process, we distinguish:

Seborrheic dermatitis with erosions.
It occurs in the course of multi-fold breakouts (intertrigo) and skin bacterial overgrowth syndrome.
The following changes are present:
- itching, erythema, seborrhea with numerous scales, around the folds, auricles, breastbone, armpits, groin or abdomen,
- skin discoloration may be visible in these places,
- as a result of intense itching and self-injury, oozing erosions may occur, which are a symptom of the so-called. hot spot (superficial pyoderma),
- purulent dermatomyositis in the area of the lips may be additionally manifested by the formation of oozing erosions or ulcers accompanied by swelling in this area.
Pustular or follicular pyoderma (common with superficial pyoderma) is manifested by the presence of:
- round alopecia (most often multifocal),
- papules, pustules, epidermal flakes.
Dermatitis with ulcers and fistulas, accompanied by purulent exudate, is typical of deep pyoderma.
They may be limited, located in a given area of the body, e.g. on the bridge of the nose, around the calluses or take a generalized form (e.g. in demodicosis or deep pyoderma of German Shepherds).
Infections with the blue pus stick most often affect large breed dogs with long hair around the tail, neck and back.
There are painful vesicular lesions with blood, scabs, erosions and ulcers.

Diagnosis of purulent dermatitis

The diagnosis of purulent dermatitis is usually made on the basis of information obtained from the dog handler and a clinical examination.

It is extremely important to identify the primary disease.

Sometimes, due to the complicated pathogenesis of the disease, additional tests are necessary.

Interview - helps to systematize symptoms and make a list of differential diagnoses.
Age of onset of the disease:
- atopy - 6 months to 6 years,
- food allergy - at any age, but if the dog is over 6 years old, a food allergy is more likely than atopy.
Race:
- food alergy:
  - bulldog,
  - Labrador,
  - Shar-pei,
  - German Shepherd,
  - cocker spaniel,
- atopy:
  - all terriers,
  - golden retriever,
  - Dalmatian,
  - West Highland White Terrier,
  - bulldog.
Seasonality of pruritus:
- strongly suggests atopy or flea allergy dermatitis,
- the lack of seasonality does not solve the problem because atopy can be year-round.
Response to glucocorticoids:
- in general, atopy is responsive to steroid therapy,
- a bad reaction to steroids suggests a food allergy or infection, but does not rule out atopy.
Lifestyle and other pets in the household:
- noticing symptoms within 3 weeks of contact with another itchy dog may indicate the presence of parasites,
- stay in a shelter, contact with wild cats, etc. also raises the suspicion of parasites.
Clinical examination:
- Characteristic changes:
  - atopy - anterior flexion surface of the elbow, back surface of the wrist,
  - flea allergy - the back surface of the back to the base of the tail,
  - scabies: auricles, elbows, sides of the body,
  - Cheyletiella - A ridge with lots of dry scales.
- Ear-foot reflex - positive in most cases of mites, negative in most pruritic diseases.
- The location of the pruritus:
  - the back half of the body - mostly fleas,
  - itching of the front part of the body - atopy, allergy.
- Current inflammation of the outer ear:
  - if there is no infection, but there is erythema - atopy mainly affects the auricle, while food allergy affects the horizontal and vertical ear canal.
  - Changes in the skin of the auricles - Sarcoptes
- Diagnostic test necessary to be performed on each patient:
  - Pap smear that detects bacteria, yeasts, and occasionally dermatophyte endospores,
  - skin scrap:
    - superficial - Cheyletiella.
    - deep - Demodex, Sarcoptes. A negative result does not exclude the presence of parasites.
- Further diagnostic tests in most cases:
  - breeding test (bacteriological and mycological) with determination of the sensitivity to antibiotics of the isolated flora,
  - skin biopsy,
  - hematological examination,
  - serum biochemical test,
  - determining the level of hormones,
  - imaging tests (to visualize bone changes or foreign bodies).
  - Antiparasitic treatment:
    - selamectin every 2 weeks (3 applications),
    - milbemycin 2mg / kg weekly for 4 weeks,
    - ivermectin 300 mcg / kg weekly for 4 weeks. Do not administer in breeds susceptible to ivermectin.
    - 8-week elimination diet followed by provocation feeding:
      - home cooked: 50:50 pinto beans / sweet potatoes.
        
        duck / potatoes, rabbit / potatoes,
      - hydrolyzed protein diet,
      - specific allergy tests,
      - serological tests.

In the case of recurrent or troublesome pyoderma, it is essential to identify the underlying disease.

How to recognize an underlying disease?

If the pruritus resolves with antibiotic therapy, the differential diagnosis should include:
- Hypothyroidism,
- overactive adrenal cortex,
- sex hormone disorders,
- metabolic diseases,
- demodicosis,
- primary keratosis disorders,
- hair follicle dysplasia,
- blackhead syndrome,
- impaired immunity,
- sun damage to the skin,
- primary hypersensitivity to staphylococci.
If the pruritus persists after antibiotic therapy has been completed, its causes should be looked for among the following conditions:
- food alergy,
- contact allergy,
- parasites (fleas, scabies, Cheyletiella, etc.),
- accompanying Malassezia dermatitis.

Treatment of pyoderma in a dog

The treatment of purulent dermatitis includes:

Treatment of the primary disease

Topical treatment is recommended for mild, superficial or local infections. In such cases, antiseptics and antibiotics in the form of creams or ointments are used.
In the case of deep, severe or generalized phlegmon, it is necessary to introduce systemic antibiotics:
- Antibiotic therapy should last a minimum of 3-6 weeks, and since the treatment of purulent dermatitis is usually long-lasting, the selection of the optimal antibiotic is crucial for the success of the therapy.
  Ideally, such an antibiotic should:
  - it was well tolerated by the animal with no or minimal side effects,
  - had a bactericidal potential against the strains causing the infection, and at the same time a fairly narrow spectrum of activity,
  - It was easy to penetrate into infected tissues,
  - was characterized by a low probability of acquiring bacterial resistance.
In the first phase of treatment, the antibiotic is selected empirically, taking into account all the above-mentioned factors and the experience of the veterinarian.
An antibiotic scan should always be recommended when the dog's purulent inflammation of the skin recurs, there are wounds that are difficult to heal, the response to current treatment is poor or the lesions spread or there are sticks present in the cytology.
The first-line antibiotics used to treat pyoderma in dogs are:
- 1st generation cephalosporins (cefadroxil 30-40 mg / kg m.c. every 12 hours orally, cephalexin 22-30 mg / kg m.c. every 12 hours orally);
- 3rd generation cephalosporins (cefovecin 8 mg / kg m.c. every 14 days subcutaneously, cefpodoxime 5-10 mg / kg m.c. every 24 hours orally);
- Amoxicillin with clavulanic acid (12.5-25 mg / kg m.c. every 12 hours orally);
- Lincosamides (lincomycin 22 mg / kg m.c. every 12 hours orally, clindamycin 11 mg / kg m.c. every 12-24 hours orally).
Second-line antibiotics should be introduced based on the antibiotic profile.
These include: clarithromycin, sulfonamides with trimethoprim, tetracyclines and fluoroquinolones.
They are used in situations where first-line antibiotic therapy did not bring the expected response.
- Enrofloxacin at a dose of 5-20 mg / kg m.c. orally every 24 hours;
- Marbofloxacin at a dose of 2 mg / kg m.c. (some authors recommend even higher doses: 2.5-5 mg / kg m.c.) every 24 hours orally;
- Difloxacin 5 mg / kg m.c. every 24 hours orally;
- Orbifloxacin 2.5-7.5 mg / kg m.c. orally every 24 hours;
- Pradofloxacin 3 mg / kg m.c. every 24 hours orally.
Third-line antibiotics are introduced in the event of treatment failure with the previous antibiotic groups and only after confirmation of bacterial susceptibility on the basis of an antibiotic profile.
In fact, they are used extremely rarely. These include:.in.: aminoglycosides, azithromycin, ceftazidime, chloramphenicol, thiamphenicol, florfenicol, fosfomycin, piperacillin and rifampicin.
- Azithromycin at a dose of 10 mg / kg m.c. orally every 24 hours;
- Chloramphenicol at a dose of 50 mg / kg m.c. orally every 8 hours;
- Rifampicin 5-10 mg / kg m.c. every 12-24 hours orally;
- Tobramycin, gentamicin, netilmycin 9-14 mg / kg m.c. every 24 hours subcutaneously.
An appropriate shampoo is used for generalized lesions, and an antiseptic for local lesions.
Topical treatment substantially shortens the time of systemic therapy while at the same time supporting the epidermal barrier and bringing visible relief to a suffering dog.
It is recommended for the treatment of superficial purulent dermatitis shampoo therapy with the use of 3-4% chlorhexidine for 2-4 weeks with the frequency of bathing: twice a week.
For limited lesions, you can use creams with 2% mupirocin, 2% fusidic acid or 1% sulfadiazine.
Aggressive flea control.
Anti-inflammatory treatment.
Steroid drugs can be helpful in treating acute dermatitis (the so-called. hotspot), but their use should be carefully considered.
They are contraindicated in demodicosis or deep pyoderma. If they are introduced, it should be for the shortest possible time.
Immunomodulation.
After 2-3 weeks, a follow-up visit, during which the caregiver will assess the severity of itching, smell and skin appearance on a scale of 1-10. Then the Pap smear should be repeated as well.
- If the response to treatment is good, treatment should be continued for another 1-2 weeks before proceeding to maintenance treatment.
- If there is no improvement, evaluate all causes of failure.
  - If antibiotic resistance is suspected, an antibiotic scan should be performed.
  - The scrap test and dermatophyte culture should also be repeated.
- If dermatitis persistently fails to respond to proper treatment, a skin biopsy should be performed.
Maintenance therapy:
- treatment of the primary disease,
- shampoo therapy every 1-2 weeks,
- supportive treatment.

Supporting general treatment of pyoderma

Topical ointments and creams containing the most common:
- Mupirocin. It is an antibiotic produced by Pseudomonas fluorescens, which locally inhibits the multiplication of competing bacteria.
  Very effective against Gram + bacteria, including methicillin-resistant Staphylococcus. For obvious reasons it is not very effective against Pseudomonas bacteria.
  Penetrates well into the tissue. Useful for treating:
  - purulent dermatitis of the folds,
  - acne on the chin,
  - licking granuloma.
- Fusidic acid - it is a bacteriostatic antibiotic, produced by the Fusidium coccineum strain (a type of fungus).
  Penetrates very well through the skin, used in dogs for:
  - local pyoderma,
  - purulent inflammations caused by methicillin-resistant strains of staphylococcus.
- Silver sulfadiazine salt - used for Gram- infections, mainly in the case of:
  - ulcers,
  - open wounds,
  - burns.
Disinfecting and acidifying sprays and wipes. Useful in preventing relapse.
Baths with the use of medicated shampoos.
Water alone brings significant benefits to patients with dermatological problems. Mechanically removes irritants, dirt and allergens from the surface of the skin, softens residual scabs and dried exudate, hydrates the stratum corneum, softens keratin and reduces percutaneous water loss.
Even taking a bath without the addition of any detergents or medications noticeably reduces the severity of itching. Hydrotherapy further increases blood flow through the skin.
Useful in the treatment of deep pyoderma, cellulitis, folliculitis, furunculosis, demodicosis, open wounds and burns.
All the listed benefits of water can be enhanced by use emollients or oils, retaining water in the epidermis after thorough soaking.
The skin is a unique organ that is fully in contact with the external environment. This makes it very easy to care for and treat, and shampoo therapy is an invention that uses its potential in a brilliant way.
Therefore, shampoo therapy is used not only to support the treatment of active pyoderma, but also as a long-term treatment of chronic, recurring disease.
Advantages of bathing with medicated shampoos:
- Broad exposure to a larger area of the body than when using ointments or creams.
- Direct treatment of diseased areas with agents that are not administered generally and are excellent antiseptics.
- Very low bacterial resistance to ingredients contained in shampoos.
- Goals of shampoo therapy:
  - Mechanical removal of dirt, dead tissue and cellular debris, exudates, scabs and dead hair, as well as allergens.
  - A gentle peeling action that opens the hair follicles.
  - Reducing the amount of bacteria that cause inflammation.
  - Limiting the re-multiplication of the bacterial flora after the disappearance of the disease.
  - Restoration of the proper barrier function of the epidermis thanks to the content of moisturizing agents.
- Tips for the correct use of shampoos:
  - In long-haired dogs it may be necessary to shorten the hair beforehand. The goal is to heal the skin, and long hair can make it difficult for shampoos and other topical products to penetrate.
  - The contact time of the active foam with the skin is extremely important: it should be 10-15 minutes. Since we treat the skin, not the hair, the key is to thoroughly apply the lather and massage it deeply under the hair.
    Thoroughly massage the skin throughout the bath.
  - First of all, you should focus on the diseased and infected areas, and then scrub the rest of the body.
    We rinse in reverse order.
  - Flushing should always be done with running water and it should be continuous minimum 5 minutes. Particular attention should be paid to the thorough rinsing of hard-to-reach places, such as:
    - armpits,
    - groin,
    - around the skin folds.
  - After bathing, it is advisable to use moisturizing and softening agents, which helps restore the biochemical balance of healthy skin.
  - Therapy should be carried out 2-3 times a week with active disease, and after symptom relief once every 1-2 weeks.
- Choosing a shampoo.
  Medicinal shampoos may contain various active substances, but most often the products with antiseptic properties include: chlorhexidine, benzoyl peroxide, ethyl lactate and mixtures of acetic, boric and malic acids.
  Additionally, ingredients of shampoos can be imidazole products, used in the treatment of fungal and yeast infections.
  Other components are added to shampoos to enhance antimicrobial therapy, such as. mannose, d-galactose or l-rhamnose (they are designed to inhibit the adherence of bacteria to keratinocytes).
  - Tris- EDTA may have a synergistic antimicrobial effect by damaging the cell walls of bacteria.
  - Phytosphingosine in high concentrations, it is directly antiseptic, and additionally supports the epidermal barrier, which supports resistance to future colonization.
  - Salicylic acid with sulfur is often combined with benzoyl peroxide to enhance keratolysis and remove dead tissues and cell debris.
  - Chlorhexidine - one of the best remedies to fight bacteria from the surface of the skin.
    The bactericidal effect is obtained in concentrations 2-4%. It is also effective against Malassezia at these concentrations.
    Chlorhexidine causes damage to the microbial cell membrane, resulting in cytoplasm leakage.
    Unfortunately - ineffective against Pseudomonas and Proteus bacteria and spores.
    In patients with seborrhea, it is used in conjunction with sulfur and salicylic acid.
    In patients with pyoderma with Malassezia cytology, chlorhexidine may be used in combination with miconazole or ketoconazole.
  - Benzoyl peroxide - metabolized in the skin to benzoic acid.
    It destroys the cell wall of microorganisms, oxidizes and lowers the pH of the environment. It is a very good disinfectant, comparable to chlorhexidine.
    Used in concentration 2-3% as higher concentrations can irritate the skin.
    It works very well fatty, keratolytic and blackheads, which is indicated in patients with seborrhea, especially when combined with sulfur. The action of opening and washing out the hair follicles makes it irreplaceable bacterial folliculitis (folliculitis) and demodicosis.
  - Ethyl lactate 10% - similarly to benzoyl peroxide, it also has an antibacterial effect and a very good property to open the hair follicles.
    It has very few side effects and is therefore very useful in sensitive dogs that may react with erythema, itching or irritation to benzoyl peroxide.
  - Phytosphingosine - has antibacterial and antifungal properties, as well as supporting the reconstruction of the damaged epidermal barrier in allergic diseases.
    Acidifying shampoos are useful in preventing re-colonization, not treating active infection.

Dermatitis caused by Malassezia

Malasiosis is a disease caused by the yeast of the genus Malassezia.

They are considered to be opportunistic microorganisms that do not cause symptoms in healthy dogs with a properly functioning epidermal barrier, and in many of them they are a natural component of normal skin microflora.

Primary malasiosiosis is therefore rare, more often these microorganisms complicate the course of the underlying disease, e.g.:

allergic reactions such as atopic dermatitis,
endocrine problems such as hypothyroidism.

Certain predisposing factors to the disease, such as:

high humidity (e.g. around the armpits, groin or interdigital spaces),
hormonal disorders (leading to changes in the composition of sebum),
increased amount of staphylococci present on the skin,
malfunction of the immune system (e.g. as a result of long-term steroid therapy),
genetic predisposition, e.g.:
- bassets,
- West Highland White Terriers,
- cocker spaniels,
- Shih Tzu,
- English setters,
- dachshunds.
other factors that lower immunity and disrupt the normal barrier function of the epidermis.

Dermatitis, caused by the colonization of Malassezia organisms, is the result of a hypersensitivity reaction. It follows that even a small amount of yeast can lead to clinical symptoms of the disease.

Clinical symptoms of malasiosiosis

The disease most often affects those areas of the skin where it is easy to chaf, e.g.:

interdigital spaces,
the facial area (especially under the folds of short-skulled dogs),
skin folds around the neck or around the vulva,
anal area,
ventral surface of the tail,
armpits and groin area,
lip folds.

Yeasts are also isolated from the mouth area, the skin of the auricle (its inner surface), the outer ear canal, and the flexor surface of the elbows or neck.

It always accompanies the disease itching.

The skin changes that are observed in the course of malasiosiosis are

erythema,
oily skin,
dry seborrhea,
thinning,
baldness,
skin hyperpigmentation.

Often the infection is accompanied by oozing foul-smelling dermatitis.

Rusty brown discoloration of the hair is also possible.

The diagnosis of malasiosiosis is made on the basis of numerous yeasts in the fingerprint cytology test or the test with adhesive tape.

Treatment of malasiosiosis

Treatment of malasiasis should be simultaneous with treatment of the underlying disease (e.g. atopy).

Local treatment is recommended when symptoms are not severe and general treatment is not required.
- Shampoo therapy using preparations containing ketoconazole or miconazole (often these substances are combined with chlorhexidine).
  In the case of coexistence of oily seborrhea (which is common in Malassezia infections) and epidermal hyperkeratosis, it is recommended to use shampoos containing:
  - benzoyl peroxide,
  - selenium sulfide,
  - sulfur,
  - salicylic acid.
- With limited changes, when the infection affects, for example,. only interdigital spaces or ears, topical preparations in the form of creams, gels or ointments, containing in their composition:
  - miconazole,
  - clotrimazole,
  - ketoconazole,
  - nystatin,
  - natamycin.
General treatment.
- Ketoconazole at a dose of 5-10 mg / kg m.c. every 12-24 hours (in one or two administrations) orally for a minimum of 3 weeks or until clinical symptoms disappear.
- Itraconazole at a dose of 5-10 mg / kg m.c. every 24 hours for a minimum of 3 weeks or until clinical symptoms resolve.
- Terbinafine at a dose of 30 mg / kg m.c. orally every 24 hours for min. 2 weeks.

Flea infestations

Currently, intense infestations caused by canine flea (Ctenocephalides canis) are relatively rare, thanks to regular and effective flea prevention.

However, it would be a mistake to completely disregard these insects and forget about them in the diagnosis of pruritus.

Fleas have perfectly adapted to the parasitic lifestyle and are still among the leading causes of itching and even allergic skin conditions in dogs. It should also not be forgotten that these parasites are vectors of invasive forms of the tapeworm Dyphilidium caninum.

Fleas are blood-sucking insects that do not stay on the skin all the time. The main habitat of larval and adult animals, the environment (e.g. lairs, carpets, floor joints, etc.).

Females lay tens of thousands of eggs daily, which end up in the dog's immediate environment.

As you can see, the presence of fleas on a dog does not have to be overt, and it is not necessary to have direct contact with another, flea-filled animal for our pet to become the host of a happy company.

This is important because many dog handlers are vehemently, sometimes even hysterical, against the suggestion that their dog has fleas.

I calm down and explain: of course it can.

And it is not at all a symptom of a special lack of hygiene or neglect.

Yes, frequent baths, staying in a clean environment and regular prophylaxis eliminate the risk of invasion, however, even couch dogs can bring stowaways, e.g. after playing in the garden.

So the sudden onset of itching may be due to the presence of fleas.

The matter is further complicated by the fact that many dogs develop an allergy to allergens contained in flea saliva, which is clinically manifested in the form of symptoms of flea allergy dermatitis.

Why flea prevention is so important?

Parasite infestations that cause itching affect the condition of the hair and skin. When rubbing, biting or scratching, hair becomes matted, matted and tangled. The skin can become infected with intense scratching, which additionally aggravates the itching and makes the matter even more serious.

Allergens contained in flea saliva can trigger flea allergy dermatitis.

Fleas are tapeworm vectors, therefore it is important to deworm your dog after a flea infestation.

The symptoms of an invasion are first and foremost severe itching.

Local inflammatory reactions may appear on the skin.

In the event of a mass invasion, anemia and cachexia may appear. This is often seen especially in young, neglected dogs.

Flea infestation treatment

There are many preparations on the market that are designed to combat ectoparasites in dogs.

The most common active substances in these preparations are:

Fipronil (Fiprex, Effipro, Flevox, Controline);
Imidacloprid, often in combination with permethrin or flumethrin (Advantix, Foresto);
Propoxur in combination with flumethrin (Kiltix);
Selamectin (Stronghold);
Fluralaner (Bravecto);
Permethrin (Ektopar, Duowin Contact);
Pyriprole (Prac-tic);
Spinosad (Comfortis, Trifexis);
Afoxolaner (NexGard).

When fighting flea infestations, remember to thoroughly clean your dog's environment.

You should wash the bed, thoroughly vacuum the carpets, and even use chemicals designed for this purpose.

An invasion of scabies

Sarcoptosis - Hollowing scabies.

Hollowing scabies Sarcoptes scabiei var. canis is the cause of extremely intense pruritus in dogs.

Symptoms of invasion are most often noticeable initially on the head (the skin around the eyes and the edges of the auricles), but the typical changes are usually:

in the lower abdominal region,
in the lower chest area,
in the area of the sternum,
on the limbs (often on the elbows and on the skin of the tarsal area).

The itching and skin lesions spread rapidly, often affecting the entire body.

Clinical symptoms of sarcoptosis

Characteristic is - the aforementioned - extremely intense itching, which does not respond to the supply of glucocorticosteroids (or the response is very weak) and increases in severity in warm areas of the body.

It is not seasonal - it can appear at any time of the year.

Presence is typical erythema, papules and scabs on the skin, and as a result of persistent scratching, post-pruritic changes appear in the form of hair thinning, alopecia, abrasions, abrasions, and even extensive damage to the epidermis.

With chronic course, it comes to skin thinning, thickening and discoloration.

In the case of self-mutilation, development often occurs secondary bacterial infections.

Sarcoptosis is very contagious.

Infection occurs as a result of direct contact with infected animals, and even objects with which the dog has come into contact. So, similar symptoms can be observed in other dogs that our pet is in contact with.

The diagnosis of the disease is made on the basis of:

Characteristic clinical symptoms (including very intense itching);
The presence of the ear-limb reflex;
Demonstration of the presence of the parasite (its developmental forms or eggs) in the skin scrapings.
Attention! A negative result of scraping does not rule out the presence of scabies!
In doubtful cases, a skin biopsy is performed with histopathological evaluation.
Occasionally, a stool examination reveals the presence of scabies eggs. They get into the digestive tract when biting and licking itchy areas of the skin.
Serological examination for the presence of specific antibodies. The method is sensitive and specific, but may not be sufficient in cases of early invasions when antibodies to Sarcoptes have not yet been developed. Antibodies are usually detected after about 5 weeks of invasion. Additionally, cross-reactions between S. scabiei and house dust mites, resulting in false-positive results in mite-allergic dogs.
Diagnosis based on response to anti-scabies treatment. It happens that none of the above methods gives a final solution. If, after the therapy, the patient's clinical condition improved, it is considered that the cause was an infestation of scabies.

Treatment of sarcoptosis

Treatment involves both topical and systemic medications and is usually of duration 4-6 weeks.

Topical Treatment:
- Amitraza at a concentration of 0.025% in the form of a bath every 14 days. Usually 2-3 baths are necessary.
- For puppies, fipronil spray is recommended at a concentration of 0.25% in a dose of 3 ml / kg m.c. 3 times at 3-week intervals.
  In adult dogs, fipronil is administered as two administrations at a dose of 6 ml / kg m.c. with an interval of 1 week, however, treatment with this agent is not always effective.
- Combination of fipronil and amitraz in the form of spot-on preparations - twice a month apart.
- Moxidectin in a 2.5% solution with 10% imidacloprid spot-on solution at a dose of 0.1 ml / kg m.c. 2 times every 4 weeks.
- Selamectin in spot-on preparations at a dose of 6-12 mg / kg m.c. Given twice with a 30-day interval.
Systemic treatment:
- Ivermectin at a dose of 0.2-0.4 mg / kg m.c. administered subcutaneously 2-3 times with an interval of 2 weeks or orally min. 3 times at 7-day intervals.
  Possible resistance of Sarcoptes scabiei var canis to ivermectin.
- Doramectin 0.2 mg / kg m.c.
- Milbemycin oxime at a dose of 2 mg / kg m.c. orally every 7-14 days for 3-5 weeks.
Treatment of complicating diseases, e.g. seborrheic dermatitis.
Sulfur- or tar-containing anti-seborrheic shampoos are used.
Elimination of pruritus - with really severe itching, you can implement:
- glucocorticosteroids, e.g. prednisolone or prednisone at a dose of 1 mg / kg m.c. orally,
- oclacitinib by mouth.
Fighting secondary bacterial infections:
- antibiotic therapy,
- shampoo therapy with the use of local antiseptics.
Combating scabies in the environment:
- decontamination of hygiene instruments,
- decontamination of dog brushes and combs,
- washing the dog bed,
- thoroughly disinfecting the places where the dog is.

Ear mites

Otodectosis - a disease caused by ear mites Otodectes cynotis is relatively rare in dogs.

When mite infestation occurs, it is most commonly found in miniature breeds, e.g. yorkshire terriers or maltese dogs.

Its main symptom is inflammation of the external auditory canal with the presence of a large amount of dark brown wax.

It is in this discharge that the various developmental forms of scabies along with their secretions are present.

Otodectosis is accompanied by itching, which is caused by the irritating effect of a large number of parasites. Hypersensitivity mechanisms may also be involved in its formation.

It happens that the invasion is complicated by yeast or bacterial infections.

As a result of itching, skin changes may occur around the auricles, as well as the neck or face.

Diagnosis is made on the basis of microscopic examination of scabies in the earwax. Occasionally, the otoscopic examination shows light-avoiding mites.

Treatment of otodectosis

Topical treatment. Before applying topical medications, the ear canal should be cleaned of any residual earwax.
- Ivermectin in a 0.1% solution administered 0.5 ml into the ear canal every 7 days or
  combined preparations, intended for the treatment of otodectosis, may include:
  - permethrin,
  - glucocorticosteroids,
  - antibiotic,
  - antifungal drug.
Systemic treatment:
- Selamectin in the form of spot-on at a dose of 6 mg / kg m.c. administered twice every 30 days;
- Combination of 10% imidacloprid with 1% moxidectin spot-on administered twice monthly;
- In case of severe itching, glucocorticosteroids can be used (similar to sarcoptosis).

Chelyletelosis

It is a disease caused by mites of the genus Cheyletiella (Cheyletiella yasguri is the most common in dogs).

Its characteristic feature is dog dandruff.

Infestation with these mites causes a significant amount of scales to form, especially on the dog's back, which is usually associated with it intense itching.

The scales can move, hence the common name of this disease "migratory dandruff ".

With long-lasting pruritus, post-pruritic changes may appear:

quarrels,
hair thinning,
baldness,
scabs on the skin.

The diagnosis of the disease is not difficult and is based on the presence of parasites.

This can be done with the de-brushing test - the material taken with a dense comb or brush is applied to dark paper and observed under a magnifying glass or microscope.

Another way is to do an adhesive tape test or a superficial scrape.

Treatment of cheletelosis

External treatment:
- Preparations containing 0.25% fipronil (2-3 times every 1-3 weeks);
- Fipronil as a spot-on administered monthly;
- Spot-on preparations containing permethrin;
- Selamectin spot-on at a dose of 6 mg / kg m.c. given monthly.
General treatment:
- Ivermectin at a dose of 0.2-0.3 mg / kg m.c. subcutaneously every 2-3 weeks or orally every week for 6-8 weeks;
- Milbemycin oxime at a dose of 2 mg / kg m.c. orally administered weekly for 8-9 weeks.

Thrombiculosis

It is a disease caused by a species of mite called Eutrombicula (Neotrombicula) autumnalis.

Another name for this disease is autumn itch, and it stems from the fact that infection most often occurs in late summer.

The most troublesome clinical symptom of the disease is itching, often really intense. Changes in the form of erythema, papules, scabs and scales usually appear in the area of:

foot and palmar limbs,
head (especially around the auricles),
belly.

Any areas in contact with the ground may show skin lesions and itching. The invasion may be accompanied by hypersensitivity, which further exacerbates the itching sensation.

The diagnosis is made on the basis of demonstrating parasites (parasitic forms are larvae, adult forms live in the ground) in a superficial scrap or in a test with adhesive tape.

Treatment of thrombiculosis

The same treatment can be used to treat this disease as for cheylletelosis.

In the case of severe itching, it is possible to introduce short-term steroid therapy, e.g. prednisone at a dose of 1 mg / kg m.c.

In the presence of bacterial complications, antibiotics and / or external therapy in the form of shampoos and antiseptics.

Demodicosis in a dog

Demodex is caused by 3 species of Demodex:

Demodex canis and Demodex injani (living in hair follicles and sebaceous glands),
Demodex cornei (living in the stratum corneum).

Demodex mites are mites that occur physiologically on the skin of dogs. They colonize the skin practically right after giving birth, passing from mother to offspring.

Under normal conditions, they do not cause lesions, but in certain situations their excessive multiplication may occur, as a result of which the symptoms of demodecosis (i.e. demodicosis) manifest themselves.

When that happens?

It is believed that the main cause of the overgrowth of these mites is a decrease in the dog's immunity.

There are several critical moments in the life of puppies when the immune system may be weakened, including,

post-weaning time,
change of environment,
nutrition with a deficiency diet.

That is why demodicosis is most often diagnosed in young dogs. However, the disease can appear at any age and many factors can contribute to its pathogenesis:

The already mentioned weakening of immunity (most often related to stress, but also as a result of other diseases, e.g. pyoderma, worming or primary immune disorders).
Genetic tendencies - dog breeds predisposed to the appearance of the disease are:
- English bulldogs,
- french bulldogs,
- dobermans,
- West Highland White Terriers,
- terriers,
- Shar-pei breed dogs.
Endocrine disorders (hyperadrenocorticism, hypothyroidism);
Long-term therapy with immunosuppressants (e.g. glucocorticosteroids);
Nutritional deficiencies;
Neoplasms;
Diabetes.

The local demodicosis usually appears as juvenile, appearing between 3 months of age. a 18. one month of age (usually under the age of 6). month), although it can also occur in older dogs.

Local hair thinning and oval alopecia are characteristic, mainly on:

head,
eyelid area,
ears,
sometimes on the peripheral parts of the limbs, the back and the lateral surface of the chest.

In these places, it often appears:

erythema,
scales,
thickening of the epidermis,
inflammation of follicle.

In the case of local demodicosis, the lesions are very well treated, and the disease may sometimes disappear spontaneously as a result of the animal acquiring natural immunity.

Generalized demodicosis can occur in both young and old animals, usually over 3 years of age. age.

And here there are thinning, alopecia covered with scales, but the changes are extensive and accompanied by:

purulent inflammation of the skin,
furunculosis,
pustules,
exudation.

As an uncomplicated disease, demodicosis does not cause pruritus.

Only when complicating processes occur, most often in the form of purulent inflammations of the skin, the dog shows itching of varying severity.

In order to diagnose demodicosis, a deep skin scrap and microscopic examination (including hair assessment) is performed.

In the event of difficulties in diagnosis, it is reasonable to perform a skin biopsy, especially in breeds such as:

shar-pei,
English bulldog,
chow-chow.

With the accompanying pyoderma, a cytological examination is performed on the sites affected by the lesions.

Treatment of demodicosis

Treatment of demodicosis, especially its generalized form, should be multidirectional.

In many cases, fighting Demodex alone is not enough. It is also necessary to support the immunity and sometimes to treat the concomitant bacterial infection.

The therapy should be accompanied by skin care - it is recommended in the presence of blackheads shampoo therapy with the use of benzoyl peroxide.

Before starting treatment, it is often necessary to groom the dog to facilitate contact of the medications with the skin.

Moxidectin + imidacloprid (spot on formulation) once a week.
Amitraza in a concentration of 0.05 to 0.1%, applied directly to the skin in the form of a nap, usually every 1-2 weeks.
It should not be used in the case of skin damage, phlegmon, and mucous membranes. You should take into account the possibility of side effects, such as:
- vomiting,
- diarrhea,
- decrease in appetite,
- apathy, etc.
Ivermectin 1% daily orally at a dose of 0.1-0.6 mg / kg m.c.
The drug may be toxic to dogs with a mutation in the MDR1 gene.
The following are particularly at risk:
- Scottish Sheepdogs collie,
- Shetland sheepdogs,
- bobtails,
- Australian Shepherds,
- German Shepherds,
- longhair whippets,
- silken windhound.
Doramectin at a dose of 0.6 mg / kg m.c. (treatment should be started at a lower dose: 0.3 mg / kg m.c.).
It is effective in treating demodicosis, but is associated with a large number of side effects.
Some animals showed neurological symptoms, visual disturbances and even coma.
Milbemycin oxime at a dose of 0.5-2 mg / kg m.c. orally once a day.
Fluralaner - orally administered according to the manufacturer's recommendations with regard to the dog's body weight.
Afoxolaner administered orally at a dose of 2.5 mg / kg m.c..
The administration may be repeated one and two months after the start of therapy.
Antibiotic therapy to combat bacterial skin infections.
Beta-glucans to stimulate the immune system.

Control skin scrapings are made every 3-4 weeks.

If, on microscopic examination, dead adults of Demodex mites and no juvenile forms are found, it means that the treatment is effective, but the therapy should continue for a minimum of 1 month from the moment of finding the absence of Demodex in 2 consecutive scrapes, taken at an interval 2-3 weeks.

See also the article: "Demodex in dogs ".

Licking granuloma

Dermatitis of the peripheral parts of the limbs caused by licking, i.e licking granuloma is one of the 10 most common dermatological skin conditions in dogs.

It is not always accompanied by pruritus (at least in the initial stage), but its basic symptom, which is licking, necessitates the use of a diagnosis identical to that in diseases with pruritus.

It is a bothersome, frustrating, expensive, tiring disease for the patient, poorly responding to treatment and often relapsing.

Therapeutic success is achieved in approx 20-65% of cases. These are not optimistic statistics.

This disease is characterized by such intense licking that it leads to self-mutilation, which in turn results in the formation of skin lesions on the peripheral parts of the limbs in the form of stout, proliferative, erosive or ulcerative, balding plaques or nodules.

The clinical picture may vary, but a common feature of all cases is persistent and excessive licking.

This intense licking causes inflammation of the skin, and the dog itches it, making the licking even more permanent.

In this way, a vicious pathophysiological circle is established.

The skin lesions usually occur on the dorsal surface of the wrist and may spread downwards to the metacarpus or upwards to the elbow.

Less commonly, they appear on the skin of the lateral surfaces of the metatarsus or tarsus (in the pelvic limbs).

The lesions are often painful to the point that the dog resists touching these areas, and may show decreased activity and even limp.

The disease can appear in any breed, but large-breed short-haired dogs are predisposed, such as:

doberman,
great dane,
Labrador,
boxer,
Weimaraner.

Often ALD is also found in:

German Shepherds,
golden retrievers,
Irish Setters.

There is one important feature in common in these dogs: the relatively short hair on the dorsal surface of the limbs. The average age at which symptoms are observed is about 4 years.

The causes of a licking granuloma are numerous, and they are really complex. They can be classified into 3 main groups as:

Predisposing factors.
These are factors that do not cause disease directly, but increase the likelihood of initiating symptoms and later progressing. There are factors such as:
- the already mentioned belonging to one of the large, short-haired breeds,
- the dog being outside only,
- no walks and entertainment provided,
- the presence of other behavioral problems.
Primary factors.
These are any conditions that trigger a licking in a specific place, causing changes to occur:
- diseases that cause itching (e.g. food allergy, atopic dermatitis),
- orthopedic trauma,
- tumor,
- fungal infection,
- foreign body,
- neuropathy,
- behavioral disturbances, e.g. separation anxiety, phobia, other stereotypical behaviors (e.g. tail chasing, circling, catching flies, barking etc.),
- Possible triggers are also:
  - the presence of stabilizers,
  - lymphoma,
  - mast cell tumor,
  - leishmania.
Fixing factors.
These are all states that result from licking and that compound this cycle of self-harm. These include, among others:
- deep bacterial skin infections.
  The most commonly isolated bacteria are Staphylococcus, Pseudomonas and Enterobacter,
- ache,
- damage to the hair follicles.
  The remains of keratin trapped in the skin cause pain and inflammation. In this situation, licking as a manifestation of pruritus can cause bacterial folliculitis, which is also pruritic and provokes more licking.
  In short-haired breeds, licking causes hair follicles to break, and short, stiff hairs to grow into deeper layers of the skin. Keratin is extremely irritating to tissues and causes deep, acute and chronic inflammation.
- inflammation of the apocrine glands,
- skin fibrosis,
- enhanced behaviors.
  Behavioral disorders contribute more to the deepening and perpetuation of an already existing disease than to causing it. Repetitive compulsive licking in dogs with ALD is compared to human obsessive compulsive disorder.

Little is known about the neurophysiology and neurochemistry of dogs with ALD, but studies in humans with obsessive-compulsive disorder have shown that some patients have an abnormal neural pathway between the frontal lobes (responsible for awareness and perception) and the caudate nucleus of the basal ganglia (responsible for planning and making movements).

As a result, patients with obsessive-compulsive disorder engage in repetitive, impulsive behaviors, such as:

Hand washing,
checking the light,
door locks, irons etc.

The patient is fully aware that he has just washed his hands, but the information that the action has been completed and is no longer needed is not properly processed and the patient repeats this behavior.

This pathomechanism may work in dogs with certain stereotypes, but it is unlikely in dogs with ALD.

In addition to abnormalities in the neural pathway, people with obsessive-compulsive disorder have low serotonin activity.

Serotonin it is an essential neuromodulator involved in almost every aspect of behavior, response, and action. Repetitive activities in patients increase serotonin activity, creating a feedback loop that enhances behavior.

Dogs with ALD may experience this type of amplified feedback where licking provides a rapid change in discomfort (e.g. relieves itching or pain) and at the same time results in a pleasant increase in the activity of serotonin in the central nervous system.

This thesis is confirmed by a partial clinical improvement in patients after the use of selective serotonin uptake inhibitors.

Diagnosis of licking granuloma should be based on the identification of both the root cause and the factors that maintain licking. Thus, the diagnostic process should begin with a thorough interview with the caregiver, with questions taking into account not only dermatological symptoms, but also observed abnormalities in behavior.

Due to possible allergic, parasitic, or infectious causes, it should be done thorough dermatological examination with collection of material for cytological, parasitological, as well as bacteriological and mycological examination.

It is also recommended to do biopsy for histopathological confirmation. Histopathology is the most direct method of excluding organic causes, such as cancer or deep mycoses.

Subjecting the dog to an elimination diet may be necessary in identifying the cause of ALD.

If, after 8-12 weeks of dieting, your pet is less interested in its paws, is no longer licking as before, and the lesions have started to heal - it may indeed be a food allergy, but it may as well be the result of treating the infection alone.

It is therefore necessary to re-provoke the dog with an earlier, potentially allergenic, diet.

Intradermal or serological tests may be helpful in determining the type of allergens, as well as introducing specific immunotherapy, especially if the dog is not responding to the elimination diet attempt.

It may also be advisable to take X-rays of the licked limbs in order to exclude a possible orthopedic cause (e.g. osteoarthritis, cancer, etc.).

The periosteal reaction visible on the x-ray is a negative prognostic factor.

Treatment of a licking granuloma

There are three key elements to consider when initiating treatment:

Elimination of pain

The importance of pain is underestimated in ALD in dogs and is often downplayed.

Pain may result from trapped hair or deep pyoderma. This provokes the dog to "compulsively" lick.

Indeed, orthopedic or neuropathic pain may be the main causes of intensive licking, so it is necessary to consider the introduction of painkillers, e.g. non-steroidal anti-inflammatory drugs.

There are reports of supporting the analgesic effect with therapy combined with gabapentin and / or amantadine.

Gabapentin is an anti-epileptic medicine, but it is also used to treat neuropathic pain.

Effective antibiotic therapy

95% of the time the disease is accompanied by deep bacterial infections.

Unfortunately, the triggering microorganisms are less predictable than typical pyoderma.

A safe, effective and convenient antibiotic is introduced that the animal will tolerate even for a long time.

It is best if the selection of the antibiotic is based on the antibiotic profile, but to obtain the result it is good to enter:

amoxicillin with clavulanic acid,
a cephalosporin antibiotic.

In the case of Gram-bacteria infections and in the absence of response to first-line antibiotics, fluoroquinolones (enrofloxacin, marbofloxacin) are used.

Topical application of mupirocin-containing ointment is an excellent treatment aid, especially with regard to the control of Staphylococcus (including methicillin-resistant strains).

Bathing shampoos containing benzoyl peroxide are also beneficial as they both act as antiseptic and open the hair follicles and help remove residual keratin.

However, any local action should be taken carefully as it directs the dog's attention to the paw being licked off.

Therefore, after the administration of drugs, the dog should be taken for a walk or other entertainment that will distract him from the sick places.

Primary disease therapy

This may include diet, immunotherapy, administration of cyclosporine, or steroids to break the licking cycle.

Treatment of behavioral disorders is based on two pillars:

Behavior modification.
Pharmacotherapy.

An experienced behaviorist should be consulted to establish an effective protocol. Behavior modification may include avoidance of recognized triggers, counter-conditioning, distraction techniques (e.g. environmental and social stimulation, exercise, entertainment and games).

Drug therapy with tricyclic antidepressants (clomipramine) or serotonin reuptake inhibitors (fluoxetine) may help to resolve the persistent serotonin feedback loop.

It is extremely important that the treatment is multifaceted, taking into account all 3 planes.

Insufficient action in any of these areas may result in a poor response to (even the best) treatment for other aspects of ALD, or may result in relapse or progression of the disease.

Other treatments like laser therapy, surgery, cryotherapy, acupuncture etc. bring variable results.

Bandaging the paws, putting on an Elizabethan collar or a muzzle to stop the dog from licking it has various effects.

I am cautious about these types of behavior reduction techniques, especially at the beginning of treatment, as they can be counterproductive.

Pain and itching are usually high and the urge to lick is very strong. The places secured with a bandage are usually licked even more intensively, and the collar or muzzle increases stress for the patient.

Other diseases that may be accompanied by itching

There are still many diseases associated with itching, and some are so unusual that even many dermatologists rarely see them. Describing all of them is beyond the scope of this study.

In addition to the above-mentioned, most common causes of pruritus, its diagnosis should also include:

internal diseases (kidney disease, liver failure),
neuropsychogenic factors,
contact dermatitis (due to contact with an irritating or allergenic agent, e.g. collar),
autoimmune diseases,
drug itching,
internal parasites,
inflammation of the external auditory canal (very often accompanies atopy, food allergy and parasitic diseases),
mycoses,
hormonal disorders (hypothyroidism, hyperadrenocorticism, idiopathic male feminizing syndrome, hyperestrogenism in bitches),
metabolic disorders (diabetes, hypercalcemia, food-related dermatoses),
another.

Summary

Summing up this quite extensive article, I would like to draw your attention to a few important issues that should be understood by every owner of a scratching dog.

Itching is a phenomenon so complex, with so many triggers, that there is no one universal way to combat it. In many cases, the elimination of pruritus is preceded by a long diagnostic process and tedious dealing with a number of symptoms and accompanying diseases.

Pruritus therapy (especially chronic pruritus) includes not only antipruritic drugs, but also:

treatment of complicating infections and parasites,
dog care at home,
use of various topical preparations,
avoiding exposure to allergens (environmental or food),
regular contact with a veterinarian.

The cooperation of the caregiver with the doctor is extremely important.

Nothing can be overlooked in the conversation, every detail revealed, every new symptom reported.

Pruritic dermatoses are extremely dynamic diseases. Today the doctor in the office can see scabs on the surface of the body, but a few days ago there were papules or pustules.

All of this is of great clinical importance.

The doctor needs to know what the direction of the disease is and how it changes over time.

Difficulties in controlling itch or even treatment failure are rarely the result of the physician's limited knowledge.

Knowledge of the pathomechanism of itching, accompanying or complicating diseases, as well as methods of therapy are not a secret for us, but sometimes it is enough for something as "natural " to appear as bacterial resistance to antibiotics, and our entire intricately woven therapeutic plan in an instant it crumbles like a house of cards.

It is understandable, of course, the impatience of the caretakers of the scratching dog, who are waiting for real help from the doctor, and it turns out that there is no improvement.

In this study, I tried to describe numerous factors that affect the severity of itching and its course. Often the treatment of complications itself is a laborious and long-lasting process, but it is necessary.

Just because the pruritus has resolved after the skin infection has been dealt with, does not mean the dog is not suffering from atopic dermatitis.

Unfortunately, it often happens that animal keepers refuse further diagnostics after antibiotic therapy has been completed and the clinical condition has improved. After some time, dissatisfied return with the same symptoms in their pet, accusing the doctor of incompetence.

It's not like that.

In dermatology, there is the concept of "summation of itching effects".

Imagine that a certain itch-inducing stimulus might not be strong enough to cause itch. However, if another factor joins it (which may also be too weak to induce scratching), the combination of both causes the itch threshold to be exceeded and scratching occurs.

This is often the case in dogs suffering from atopic dermatitis, joined by a secondary bacterial or yeast infection.

Treating the infection alone can then keep the animal below the pruritus threshold.

But that doesn't mean there is no atopy:

it is simply asymptomatic.

It is enough, however, that some other pruritic factor takes effect and the pruritus is revealed in all its glory.

The use of antipruritic drugs is not always necessary.

If we identify the cause of the pruritus quickly enough and implement effective causal treatment, the pruritus may resolve itself.

Some even believe that the best "antipruritic " drugs are insecticides and acaricides, antibiotics and antifungal agents.

Dry skin itches more, which is why taking care of its proper hydration is crucial in the therapy supporting the treatment of itching.

Frequent bathing in appropriate shampoos adapted to the disease, the use of moisturizing and regenerating preparations for the damaged epidermal barrier can significantly reduce itching, and thus bring relief to the suffering animal.

Sources used >>

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