Home » other animals » Lack of Appetite in Dogs: Causes and Illnesses of Which Loss of Appetite Is a Symptom

Lack of Appetite in Dogs: Causes and Illnesses of Which Loss of Appetite Is a Symptom

Lack of appetite in the dog

Has your pooch have lately worse appetite and sometimes he is "picky"?

Or maybe he had completely lost interest in a full bowl?

It's good to know that lack of appetite in the dog can be a symptom of serious diseases.

What? You will learn from this article.

I will also explain why it occurs a decrease in the dog's appetite and when to start worrying.

  • When we talk about a dog's lack of appetite?
    • My dog ​​refuses to eat - when to go to the vet?
  • Regulation of food intake
  • The cause of the dog's lack of appetite
    • Primary lack of appetite in the dog
    • Secondary lack of appetite in the dog
    • Alleged lack of appetite

When we talk about a dog's lack of appetite?

When we talk about a dog's lack of appetite?

Loss of appetite in the dog is the reduced intake of food normally eaten by the animal.

We can talk about anorexia in a dog if the animal completely refuses to eat for two days or too for three days it has been taking less than 50% of the daily nutritional dose.

Decreased food intake is usually the first symptom of illness noticed by the dog handler.

We all worry when the animal starts to eat less and becomes picky, let alone when it completely loses its appetite.

Unfortunately, food intake disorders are not specific to a particular group of diseases and may result from many factors.

Anorexia can be related to, for example:

  • stress,
  • the heat,
  • overfeeding the day before,
  • heat.

The liquid usually reduces the bitch's food intake, but it also has an effect on uncastrated dogs living in the area.

Pheromones secreted during heat are sensed by males at a distance, and non-castrated dogs that are susceptible to these signals often lose interest in eating.

Stress situations they can also suppress the dog's appetite.

Similarly unfavorable environmental conditions for example, no access to water.

However, the development of serious diseases can never be ruled out in the case of a dog's lack of appetite.

The lack of food intake may have a physiological or psychogenic background, but it is most often associated with disease processes.

In inflammation, bacterial infections, neoplasms, and after tissue injuries, numerous factors are released, such as: pyrogens, interleukins, interferons or tumor necrosis factor, impressive anorexia.

In accompanying metabolic diseases liver failure if kidney failure it produces metabolism by-products or appetite suppressant toxins.

Also bacterial toxins, anxieties if poisons can cause anorexia:

for example amphetamines directly blocks the hunger center.

My dog ​​refuses to eat - when to go to the vet?

When anorexia should bother you?

If the dog lacks appetite, it is worth trying to start with a feed with a different composition or add some warm water to the feed.

For one or two days, provided that no other disturbing symptoms appear, we can wait and observe the animal.

However, if the lack of appetite lasts longer than two or three days, it is necessary to visit a nearby veterinary clinic.

We must remember that insufficient food intake has a negative impact on all systems in the body, and especially impairs the functioning of the immune system, which is already visible after two days of fasting.

The veterinarian will first conduct an interview during the visit. Ask:

  • o the duration and circumstances of the lack of appetite,
  • o the type of feed and its possible change,
  • o reluctance to eat - is it only for certain types of food,
  • whether the animal has unlimited access to water,
  • Has there been any recent change in the dog's environment (new family member, moving house).

The accompanying symptoms (diarrhea, vomiting, constipation, weakness) and the dog's eating behavior (drooling, choking) are very important.

Then the doctor will clinically examine the animal and, if necessary, prescribe additional tests:

  • blood test,
  • urine test,
  • imaging tests.

Before visiting a doctor, let's consider the answers to these questions, so as not to miss any important information.

Regulation of food intake

The appetite is regulated by factors:

  • neurological,
  • hormonal,
  • metabolic,
  • mechanical,
  • mental.
Regulation of food intake

There are centers of hunger and satiety in the brain in the hypothalamus.

Stimulation of the hunger center leads to food intake, while stimulating the satiety center inhibits this activity.

Other centers in the brain cooperate with centers in the hypothalamus to regulate food intake, for example through the sense of smell.

The smell is helpful in making a decision about food intake - pleasant olfactory sensations stimulate the appetite and stimulate the appetite.

Along with food intake, the satiety center is stimulated and the hunger center is inhibited.

Chewing, secreting saliva, swallowing and tasting food suppresses the appetite after the right amount of food has entered the stomach.

The palatability of the meal decreases with food intake.

The filling of the stomach and intestines inhibits the hunger center by mechanically acting on the receptors in these organs.

The presence of food in the digestive tract and its digestion inhibit the hunger center by mechanical and hormonal means.

Similarly, the liver, as the main organ regulating metabolism, is involved in the regulation of satiety via the produced metabolites.

Food intake is also regulated on the basis of the body's nutritional status, the amount of adipose tissue or the concentration of glucose and amino acids in the blood.

Too little energy reserves stimulate the search for food and vice versa, too much reserves in the body suppresses appetite, stimulating the satiety center.

The cause of the dog's lack of appetite

The dog refuses to eat? "Src = " // cowsierschips. Pl / wp-content / uploads / 2017/07 / dog-vestibular-syndrome-symptoms. Jpg ”alt = ” why the dog refuses to eat? "Width = " 680 ″ height = "433 ″ longdesc = " // cowsierscuts. Pl? Longdesc = 4940 & referrer = 7250 ″ data-wp-pid = ”4940 ″ /> why the dog refuses to eat?

There are many reasons for the lack of appetite, because the regulation process itself is extremely complicated.

Many diseases suppress the appetite by disrupting the normal neurological, endocrine, and mechanical mechanisms that regulate food intake.

With infections, injuries and inflammation, the appetite is blocked by the hypothalamic release prostaglandins.

In diabetes, metabolic or endocrine diseases, lack of food intake occurs due to improper production of metabolic products.

Often, during illness, anorexia is due to the development of several interacting factors.

For example:

prolonged dilation and inactivity of the stomach induce neurological and endocrine anorexia.

For some diseases, not all the mechanisms responsible for the lack of appetite are known, as in the case of neoplastic disease.

The many causes of anorexia include:

  • no possibility of food intake,
  • pain while eating,
  • acquired taste aversions,
  • delayed gastric emptying,
  • metabolic disorders,
  • inflammation and tissue injuries,
  • desire,
  • no sense of smell,
  • diseases of the central nervous system,
  • medications taken.

Acquired taste aversions that arise during unconscious association of the consumed food with a simultaneous or emerging health disorder may be consolidated.

In the future, the animal will avoid food that it associates with health problems.

Lack of appetite, depending on the causes causing it, has been divided into:

  • original,
  • secondary,
  • alleged.

Primary lack of appetite in the dog

Primary lack of appetite in the dog

The primary lack of appetite in the dog results from a direct disease process in the nerve centers that control appetite in the brain (neurological disorders) or from factors that influence the neurological processes that control food intake (psychogenic disorders).

Neurological disorders

This includes disease processes taking place within the brain and directly affecting the centers that regulate food intake.

These are increased intracranial pressure, intracranial pain and hypothalamic diseases, in which the centers regulating food intake are located.

Increased intracranial pressure can be caused by swelling of the brain or hydrocephalus.

Intracranial pain is basically a headache that our pets can also suffer from, for example, during an attack glaucoma.

Diseases of the hypothalamus include:

  • tumors,
  • infections,
  • brain injuries.

Psychogenic disorders

Your dog won't eat? It could be stress

Psychogenic disorders are quite difficult to diagnose in dogs.

The reason for the lack of appetite may be:

  • stress,
  • change in the animal's environment (different rhythm of the day, new family member, moving house),
  • fear of, for example, the second, dominant dog.

Habits or taste aversions

Acquired habits or taste aversions are also important.

The food your dog is fed may not like your dog, so if you don't feel like eating, it's always a good idea to try a different type of food first.

Taste aversion can develop in animals during their lifetime. The dog may establish an association of illness or malaise after taking a given food, even if it is not related to it, and avoid it in the future.

Loss of smell

The smell of food is a factor regulating its intake, so loss of smell (e.g. blocked nostrils, or impaired smell in senior dogs) and taste disturbances lead to psychogenic loss of appetite.

Secondary lack of appetite in the dog

Secondary lack of appetite in the dog

Diseases that cause secondary loss of appetite develop outside the brain.

These diseases affect the neurological and endocrine mechanisms that regulate the feeling of hunger.

In the course of many diseases, substances that suppress the appetite are produced.

The causes of secondary anorexia have been classified into 7 major groups.


Severe pain is one of the factors causing anorexia by inhibiting the stimulation of the appetite center in the neural way (nerve signals block the hunger center).

Psychogenic changes leading to a deterioration in appetite are also important.

Administration of painkillers to dogs suffering from joint and muscle pains with a weakened appetite can bring a significant improvement in the amount of food consumed.

Abdominal organ diseases

Most diseases affecting the abdominal cavity are associated with a lack of food intake.

Disorders leading to the stretching of the membranes of organs, for example bowel obstruction if gastric obstruction, suppress the appetite and often cause vomiting.

Diseases of the gastrointestinal tract are usually associated with nausea or vomiting, which inhibits the hunger center in the brain.

Nausea and vomiting from other causes also suppress appetite because the brain has connections between the vomiting centers and the appetite regulators.

The inflammatory process in the abdominal cavity accompanying diseases of the liver, pancreas, stomach and intestines also causes a lack of appetite.

It is caused indirectly by the toxins produced and directly by damage to the abdominal organs.

Also, strong enlargement of the uterus at pyomyeloma or at the end of pregnancy, stimulating the nerve pathways, blocks the hunger center.

In the case of pyomyeloma, the appetite is also inhibited by toxic substances produced in the uterus.

Toxic substances

The appetite is inhibited by toxic substances of external origin and those produced in the body, for example by pathogenic bacteria.

They act directly affecting the center in the brain and indirectly damaging the abdominal organs, leading to their inflammation and necrosis.

Bacterial infections cause a lack of appetite due to the production of toxins, but it is also a concomitant one fever.

Food intake is inhibited by endogenous toxic metabolic products formed during the failure of internal organs (kidneys - uremia, liver - increased levels of ammonia, pancreas - diabetes - ketoacidosis).

Endocrine disorders

IN adrenal insufficiency, that is Addison's disease, insufficient production is most likely responsible for the lack of appetite glucocorticosteroids.

In untreated diabetes, ketoacidosis develops and ketone bodies are produced, which is often associated with loss of appetite.

Elevated calcium levels present at hyperparathyroidism, but also in other diseases such as cancer, it usually causes anorexia.

Occasionally, with hypothyroidism, you may encounter a decreased appetite, although in the vast majority of cases it is an excessive appetite.


Poor appetite, or lack of appetite it is one of the most common and sometimes the only symptom in neoplastic diseases.

Cancerous growth leads to production peptides blocking mechanisms that regulate appetite.

They are also possible taste disturbance, nausea favoring reduced food intake.

Poor appetite leads to neoplastic cachexia, i.e cachexia.

The development of cancer cachexia and anorexia are also influenced by other factors produced by the cancer, such as:

  • tumor necrosis factor,
  • factors inducing lipolysis and proteolysis,
  • interleukins,
  • interferons.

Infectious diseases

All bacterial diseases, viral, fungal if protozoa may be the cause decreased appetite.

This is due to the action of bacterial toxins and the occurrence of fever.

Increased body temperature, regardless of the triggering factor, always adversely affects food intake.

the remaining

Other causes of loss of appetite include:

  • heart failure,
  • long-term malnutrition,
  • dehydration,
  • desire,
  • high ambient temperature,
  • motion sickness,
  • inner ear diseases,
  • autoimmune diseases,

Alleged lack of appetite

The alleged lack of appetite results from difficult food intake while maintaining appetite.

The dog is eager to eat but is prevented or impaired from taking, chewing or swallowing food.

The cause is usually diseases affecting the mouth and head, such as:

  • inflammation,
  • injuries,
  • fractures,
  • tumors.

These can be dental diseases (fractures, periapical abscesses), dislocations or fractures of the mandible or maxilla.

Also, a strong inflammation of the mouth, throat and esophagus caused by bacterial infections, foreign bodies, irritants (toxins - uremia, chemicals) or autoimmune diseases should be mentioned.

Food intake is also hindered by paralysis of the nerves (lingual, mandibular branch of the trigeminal nerve) or muscles responsible for chewing and swallowing (muscle inflammation, injuries, autoimmune diseases, tetanus, rabies).

Eye disorders also negatively affect food intake.

These can include orbital conditions such as inflammation, abscess if head tumor, and blindness.


Lack of appetite in the dog

Hope you already know after reading this article lack of appetite in the dog is a symptom that cannot be underestimated.

However, if this condition does not last long, there is no need to panic, because eating disorders may well be caused by stress.

If you have questions about this topic, post them under the article or on the psy forum.

Sources used >>

Leave Your Comment