Home » dog » Dog and cat blood tests: when to do and what the results mean?

Dog and cat blood tests: when to do and what the results mean?

Blood test for a dog and a cat belongs to the group of the most frequently performed additional tests.

Blood test

Itself clinical trial in many cases it is insufficient to make a diagnosis in a dog or cat, so they should be supported with skilfully selected laboratory tests.

Doctors usually start with blood tests.

And indeed - this body fluid provides a lot of information, both about the general condition of the body and the activities of its individual organs and systems.

Blood tests not only help to guide the diagnosis and select appropriate additional tests, they also provide valuable tips on choosing the optimal treatment, play an essential role in monitoring the effectiveness of therapy and, finally, are one of the most important prognostic factors.

A blood test should be performed before any surgery

Blood tests should be performed routinely before any surgery to estimate the degree of risk.

Blood test can be conventionally divided into morphological study and serum biochemical test.

Morphological study, popularly known as "morphology " informs us about:

  • red blood cell count,
  • white blood cell count
  • platelet count.

Biochemical research in turn, they provide valuable information regarding the functioning of internal organs.

Both of these tests complement each other, giving the physician a better picture of the patient's clinical condition and often allowing the diagnosis to be made (or at least suspected) without having to resort to additional, possibly more invasive, diagnostic methods.

Sometimes they are not fully sufficient, then the diagnostic panel needs to be extended to include other tests and blood tests.

However, in the majority of cases they are the first, basic and key analytical tests.

It may not be easy to interpret the results of blood tests in this article I do not encourage self-diagnosis on the basis of data obtained through laboratory analyzes.

It happens that the results obtained are seemingly contradictory, mutually exclusive or also that the patient's clinical condition does not match what is shown on the printout.

Only a comprehensive, in-depth analysis of clinical symptoms, test results, and often the response to treatment, can help in making a diagnosis.

Therefore, I appeal to the information contained in this article should rather be treated as informative, theoretical.

My goal is to present the complicated abbreviations and numbers that appear on the results of laboratory analyzes, which are completely incomprehensible to animal keepers.

I provide reference ranges that may differ between studies and laboratories.

I generally outline the diseases under which individual parameters may increase or decrease, and I present the most commonly used diagnostic profiles in diagnosing diseases in dogs and cats.

I invite you to read ?

  • Blood morphology in dogs and cats
    • Hemogram interpretation
    • Erythrocytes, red cells (E, Ery, RBC)
    • Hemoglobin (Hb, HBG)
    • Hematocrit (Ht, HCT, PCV)
    • MCV
    • MCH
    • MCHC
    • Qualitative assessment of red blood cells
    • Inclusions
    • Parasites
    • Regenerative anemia
    • Non-regenerative anemia
    • White blood cells (Leukocytes, L, WBC)
    • We divide white blood cells into:
    • Neutrophils
    • Eosinophils
    • Basophils (Basophils)
    • Lymphocytes
    • Monocytes: the largest white blood cells
    • Platelets (Thrombocytes, PLT)
  • Coagulogram
    • Bleeding time
    • Clotting time
    • Activated Clotting Time (ACT)
    • Cephalin Time (PTT)
    • Kaolin-Kephalin Time (APTT)
    • Prothrombin Index (PT)
    • Thrombin time (TT)
    • Antithrombin III (AT III)
    • The concentration of fibrinogen
    • Clot lysis test
    • Clot withdrawal
    • Study of D-Dimers
    • Antiplatelet antibodies
    • Platelet-bound immunoglobulin
    • Factor VIII related antigen
    • Fibrin degradation products (FDPs)
  • Biochemical tests of dog and cat blood serum
    • Key points in the interpretation of biochemical test results
  • Routine biochemical tests
    • ALT - alanine aminotransferase / alanine transferase
    • AST: aspartate aminotransferase
    • ALP / AP: alkaline phosphatase
    • CIALP: Corticosteroid-induced Alkaline Phosphatase
    • ACP: acid phosphatase
    • GGT (γ- GGT): gamma glutamyltransferase
    • Ammonia
    • Amylase
    • Lipase
    • Heparin stimulation test for lipoprotein lipase
    • Bile acids
    • Bilirubin
    • Cholesterol
    • Triglycerides
    • Lipoprotein electrophoresis
    • BUN / SUN: Blood urea nitrogen
    • Urea
    • Creatinine
    • BUN / Creatinine ratio
    • Glucose
    • Glucose tolerance test
    • Fructosamine in the monitoring of hypoproteinemia
    • Fructosamine in monitoring diabetes
    • Total Protein (TP)
    • Albumin
    • Globulins
    • Viscosity test for hyperproteinemia
    • Fibrinogen and acute phase proteins
    • C-reactive protein (CRP)
    • Creatine Kinase (CK / CPK)
    • Lactate dehydrogenase (LD, LDH)
    • Uric acid
    • Lactic acid
    • Makroenzymes
  • Functional tests of the adrenal glands
    • Determination of ACTH
    • Acth stimulation test
    • Combined acth stimulation test with dexamethasone inhibition test
    • Dexamethasone inhibition test
    • Aldosterone
    • Cortisol: an indirect test
    • Serum cortisol
  • Dog and cat thyroid function tests
    • fT4: free T4
    • Reverse T3
    • T3
    • K factor
    • Thyrotropin: cTSH
    • A thyroid stimulating hormone response test
    • Free T4 by dialysis (fT4d)
    • Treatment monitoring: TSH
    • Thyrotropin Releasing Hormone (TRH) stimulation test
    • Antibodies to thyroid hormones
    • Anti-thyroglobulin antibodies
    • T4 / T3 autoantibody test
    • T4: Tetraiodothyronine
    • T3 suppression test
  • Hormone tests
    • Insulin-like growth factor-1 (IGF-1)
    • Growth hormone stimulation test
    • Insulin
    • Ratio: insulin / glucose
    • Estradiol
    • Progesterone
    • Relaksin: pregnancy test in bitches
    • Gastrin
    • Gastrin stimulation test
    • Parathyroid hormone (PTH)
    • Protein-bound parathyroid hormone (PTHrP)
  • Blood tests for gastrointestinal disorders
    • Xylose Absorption Test
    • Bentiromide Test (Bt-PABA)
    • Fat absorption test
    • Vitamin A Absorption Test
    • TLI (tripsin-like immunoreactivity)
    • Vitamin B12
    • Folic acid
    • Calcium
    • Ionized calcium
    • Chlorides
    • Phosphorus (P ++)
    • Magnesium
    • Iron
    • Potassium
    • Sodium
    • Serum sodium to potassium ratio
    • Osmolarity
    • PH
    • Bicarbonate (HCO3-, CO2)
    • Carbon Dioxide (CO2)
  • Serological and special tests
    • Antibodies against acetylcholine receptors
    • Acute phase proteins
    • Alpha-fetoprotein
    • ANA: Antinuclear Antibody Assay
    • Lyme disease
    • Catecholamines (adrenaline, noradrenaline, dopamine)
  • The most commonly used diagnostic profiles in dogs and cats
    • General diagnostic profile
    • Geriatric profile
    • Anemia profile
    • Diarrhea profile
    • Electrolyte profile
    • Dog epileptic profile
    • Renal profile
    • Claw profile
    • Diagnostics of pu / pd (polyuria and increased thirst)
    • Vomiting - diagnosis
    • Pancreatic-intestinal profile
    • Pancreatic profile
    • Hepatic profile
    • Preoperative profile
    • BARF profile
    • Cat profile
    • Profile of the upper respiratory tract
    • Hemotropic mycoplasma profile
    • Ophthalmic profile
    • FIP profile
    • Epilepsy profile

Blood morphology in dogs and cats

Complete blood count of dog and cat

Hemogram interpretation

Hemogram, that is, full blood count (or total blood count) is by definition not part of a large biochemical profile.

However, the data obtained from this blood test provides important indicators that can support biochemical findings and aid in the diagnosis and treatment of disease.

The hemogram contains both quantitative and qualitative information about blood cells.

The quantitative data of the hemogram includes:

  • total red blood cell count (RBC),
  • total white blood cell count (WBC),
  • thrombocyte count (PLT - platelets),
  • the number of differentiated white blood cells,
  • hemoglobin level,
  • hematocrit value,
  • the number of reticulocytes,
  • red blood cell indicators,
  • sometimes determination of total protein levels.

Quality marks are morphological evaluation of the blood smear.

Erythrocytes, red cells (E, Ery, RBC)

Erythrocytes are the most abundant blood cells, produced in the bone marrow and stored and degraded in the spleen.

The primary role of erythrocytes is oxygen transport - this feature is possible due to the fact that they contain significant amounts hemoglobin - a red blood dye that has a great affinity for this gas.

The analysis of red blood cells in the hemogram includes:

  • hematocrit (HCT),
  • red blood cell count (RBC),
  • a hemoglobin test and a red blood cell count shown on a blood smear.

From standard measurements, you can calculate the indicators of red blood cells:

  • mean cell volume (MCV),
  • mean cell hemoglobin concentration (MCHC).

The increase in red blood cells most often occurs with:

  • dehydration; this is a purported increase in erythrocytes that occurs as a result of a significant concentration of blood - this is how the ratio of red blood cells to plasma changes,
  • prolonged hypoxia;
  • stress; with strong emotional arousal (especially during a visit to a veterinarian), the spleen may contract reflexively and the pool of erythrocytes is released into the circulation; this apparent increase in erythrocytes may be seen in the hemogram, but is usually small,
  • certain neoplastic diseases,
  • polycythemia (polycythemia vera) - this is a rare disease of the haematopoietic system,
  • kidney cystic disease,
  • hydronephrosis,
  • treatment with corticosteroids,
  • heart failure,
  • lung failure.

The most common fall in red blood cells is:

  • as a result of hemorrhage - this is the so-called. haemorrhagic anemia (acute and chronic),
  • in the course of various types of anemia (aplastic anemia, hemolytic anemia, deficiency anemia),
  • in case of hyperhydration (apparent decrease in the number of erythrocytes),
  • in late pregnancy,
  • in the case of infestations with blood parasites - e.g. Babesia canis in dogs, Haemobartonella in cats,
  • as a consequence of renal failure; they produce a hormone erythropoietin, which is essential for the production of red blood cells in the bone marrow,
  • in the course of chronic infections,
  • with endocrine disorders such as:
    • hypopituitarism,
    • Hypothyroidism,
    • adrenal insufficiency,
    • excess estrogens.

Hemoglobin (Hb, HBG)

It is the red blood pigment that carries oxygen around the body.

The increase in the level of hemoglobin is observed:

  • in hyperhemia,
  • in case of dehydration.

A decrease in hemoglobin levels occurs:

  • with anemia of various backgrounds,
  • in the event of overhydration.

Hematocrit (Ht, HCT, PCV)

It is a value that reflects the ratio of the morphotic (or cellular) elements of blood (mainly erythrocytes) to the total blood volume.

Hematocrit is used to identify anemia (in combination with other hematology parameters) as well dehydration and overhydration (in combination with serum total protein value).

Increase in hematocrit - causes:

  • primary and secondary hyperemia;
  • dehydration, e.g. as a result:
    • diabetes insipidus,
    • vomiting,
    • diarrhea,
    • fluid loss,
  • reduction in plasma volume due to plasma loss, e.g. by:
    • burned,
    • peritonitis.

Hematocrit decrease:

  • conditions where the volume of circulating blood increases, e.g.:
    • pregnancy,
    • nephrosis,
    • hyperproteinemia - that is, excess protein,
  • anemia,
  • overhydration.

Red cell markers are mainly used to identify the type of anemia.


MCV (Mean Corpuscular Volume) is the average volume of a red blood cell.

MCV is increased at:

  • macrocytic and megaloblastic anemia (deficiency of vitamin B12, cobalt and folic acid),
  • cirrhosis of the liver,
  • hypotonic overhydration,
  • hypothyroidism,
  • physiologically in newborns.

MCV is reduced at:

  • microcytic anemia (iron deficiency);
  • chronic diseases;
  • hypertonic dehydration.


MCH (Mean Corpuscular Hemoglobin) - the average mass of hemoglobin in the red blood cell

MCH is increased at:

  • hypercolytic anemia (megaloblastic, with cirrhosis).

MCH is reduced at:

  • iron deficiency hypochromatic anemia,
  • certain neoplastic diseases,
  • hypotonic overhydration.


MCHC (Mean Corpuscular Hemoglobin Concentration) - mean concentration of hemoglobin in the red blood cell

MCHC is increased with:

  • hyperchromic anemia,
  • hypertonic dehydration.

The MCHC is lowered at:

  • hypochromatic anemia with iron deficiency,
  • hypotonic overhydration,
  • lead poisoning.

Qualitative assessment of red blood cells

Assessment of red blood cells can be determined by microscopy (blood smear assessment).

This blood test assesses:

  • the size of your red blood cells,
  • shape of red blood cells,
  • staining of the red blood cells,
  • the presence of inclusions,
  • the presence of possible parasites.

When qualifying red blood cells qualitatively, you may encounter the following terms:

  • Normocytosis - normal cell size.
  • Macrocytosis - the predominance of large cells. Macrocytes are large red blood cells, among which the following can be distinguished:
    • Megalocytes. They occur in megaloblastic anemia due to deficiency of B12 and folic acid.
    • Non-megocytic macrocytes (e.g. leptocytes) - appear in mechanical jaundice and iron deficiency anemia.
    • Reticulocytes - i.e. immature red blood cells - their increased number is a symptom of the regeneration of the red blood cell system and occurs with increased erythropoiesis (i.e. production of red blood cells).
  • Microcytosis - quantitative advantage of small blood cells. There are 2 types of microcytes:
    • Spherocytes - blood cells that do not contain the usual brightening inside.
    • Non-spherocytic microcytes (blood cells smaller and thinner than normal).

Spherocytosis it is characteristic of anemia of the immune background.

  • Anisocytosis - the presence of blood cells of different sizes.
  • Poikilocytosis - the occurrence of blood cells of various shapes. Among such red blood cells of various shapes, the following can be distinguished:
    • Ovalocytes - oval-shaped blood cells, sometimes physiologically present. They appear in the blood with megaloblastic anemia.
    • Schistocytes (also known as fragment cells) - blood cells with damaged cell membranes. They occur in diseases with disseminated intravascular coagulation (DIC), as well as after burns.
    • Thyroid cells - as the name suggests, they look like a shooting target due to the uneven distribution of hemoglobin in the blood cell. They occur in iron deficiency anemia, liver diseases and mechanical jaundice.
    • Acanthocytes - blood cells with protrusions. They occur mainly in diseases of the liver.
    • Drepanocytes - sickle-shaped cells - occur in haemolytic sickle cell anemia.
  • Orthochromasia - normal, pink-yellow discoloration of blood cells.
  • Oligochromasia (hypochromasia, hypochromia) - hypochromia of blood cells. It may be caused by a decrease in hemoglobin due to iron deficiency.
  • Hyperchromasia (hyperchromia) - hyperpigmentation of blood cells. Spherocytes, reticulocytes and megalocytes are hyper-pigmented.
  • Polychromasy - different color of blood cells. It is characteristic of the increased regeneration of the red blood cell system, e.g. in acute haemorrhagic anemia, hemolytic anemia, as well as during disorders of hemoglobin synthesis.
  • Erythroblastosis - the presence of nucleated precursors of red blood cells in the smear.


The following inclusions may appear in the blood cells:

  • Howell-Jolly cells - remains of the erythroblast nucleus - occur in severe anemia and in hemolytic jaundice.
  • Cabot rings - possibly debris from the erythroblast nucleus membrane - occur in anemia, leukemia, and lead poisoning.
  • Heinz cells - lumps of denatured hemoglobin inside erythrocytes - occur most often in poisoning, e.g. pesticides, and in dogs and cats after treatment with prednisolone.


Parasites found in blood cells:

  • Babesia sp.,
  • Haemobartonella sp.,
  • Theileria sp.,
  • Anaplasma sp.

Parasites found outside the red blood cells in the smear:

  • Leucocytozoon sp.,
  • Hepatocystis sp.,
  • Hepatozoon sp.,
  • Trypanosoma sp.,
  • Sarcosystis sp.,
  • Toxoplasma sp.,
  • Eperythrozoon sp.

The total number of erythrocytes (except for mature cells) is also included juvenile blood cells - erythroblasts and reticulocytes.

The erythroblast count is determined on the basis of the blood smear assessment, while the reticulocytes are currently estimated automatically using the analyzer.

In anemic dogs and cats, reticulocyte counts can be very helpful.

Total number of reticulocytes greater than 80,000 / μL both in dogs and in cats it suggests increased production of red blood cells in the bone marrow.

Based on such data, the main abnormalities in red blood cells can be identified and classified - anemia or polycythemia (polycytemia).

Anemia is by far the most common red blood cell disorder in animals and can be classified as regenerative anemia or non-regenerative anemia based on the number of reticulocytes and the hemogram.

Regenerative anemia

Regenerative anemias are characterized by:

  • decreased hematocrit,
  • increased number of reticulocytes
  • polychromy and anisocytosis in the blood smear.

Significantly regenerative anemias have raised MCV values and reduced MCHC values (microcytic and hypochromic anemias).

Regenerative anemias include acute and subacute anemia from blood loss as well as external and intravascular hemolytic anemias.

Rapidly developing blood loss or hemolytic anemia can severely affect other laboratory data.

Acute anemia is associated with rapidly developing hypoxia, which causes damage to the cell membranes of the parenchymal organs (e.g. liver) and the release of cytoplasmic enzymes.

Enzymes such as AST, ALT, LDH may be increased.

In general, hemolysis (that is, the transfer of hemoglobin into plasma due to damage to red blood cells) can cause increase in serum bilirubin due to increased hemoglobin turnover.

Intravascular hemolysis causes hemoglobinemia (increased serum hemoglobin levels) i hemoglobinuria (presence of hemoglobin in urine).

Hemoglobinemia can interfere with many colorimetric chemistry determinations.

Non-regenerative anemia

Non-regenerative anemias are characterized by decreased hematocrit with no response, i.e. without an increase in the level of reticulocytes.

Non-regenerative anemias can only be classified on the basis of bone marrow examination.

Generally, non-renenerative anemias result from either a maturation defect characterized by ineffective erythropoiesis (red blood cell formation), or are anemia associated with bone marrow hypoplasia.

Non-regenerative hypoplastic anemia may be caused by:

  • general bone marrow damage,
  • reduction of erythropoietin,
  • the invasion of the bone marrow by the neoplastic process,
  • bone marrow depression associated with chronic disease.
Undefined, non-regenerative anemia "chronic disease " is the most common anemia in veterinary medicine and can develop within one week or less (in cats).

In terms of MCV and MCHC, anemia resulting from a maturation defect may be macrocytic or microcytic, hypochromic.

Hypoproliferative anemia is usually normocytic and normochromic.

White blood cells (Leukocytes, L, WBC)

White blood cells are the second most abundant (after erythrocytes) in the blood.

There are several populations of white blood cells with different functions and morphology.

The main role of white blood cells is to defend the body against pathogens (bacteria, viruses or parasites).

We divide white blood cells into:

  • Granulocytes:
    • neutrophils,
    • eosinophils (oesinophils),
    • basophilic (basophils).
  • Agranulocytes:
    • lymphocytes,
    • monocytes.

The increase in the number of white blood cells leukocytosis occurs in the course of:

  • inflammation caused by bacterial infections or tissue damage,
  • certain viral infections, e.g. rabies,
  • neoplastic diseases,
  • uremia,
  • diabetes,
  • haemorrhagic and haemolytic anemia,
  • leukemia,
  • as well as from the action of adrenaline and glucocorticosteroids.

Physiological leukocytosis:

  • after exercise,
  • after feeding,
  • digestive leukocytosis (in dogs) - results from increased levels of neutrophils; it occurs an hour after feeding and lasts for 2 to 4 hours,
  • in the last stage of pregnancy and immediately after childbirth,
  • in young animals,
  • stressors - under the influence of stress factors, the number of leukocytes may increase.

Reduction in the number of white blood cells (leukopenia):

  • diseases of the hematopoietic organs (e.g. cancer, aleukemic leukemia, leukemia in remission, aplastic anemia),
  • infectious diseases (e.g. feline panleukopenia, canine parvovirosis),
  • cachexia, convalescence,
  • anaphylactic shock.
  • poisoning with drugs (sulfonamides, antibiotics, painkillers, anticonvulsants) or poisoning with chemicals (DDT, mercury and lead compounds).
  • ionizing radiation.

Just estimating the number of white blood cells is usually insufficient, especially if the blood count has not turned out correctly.

Then it is important to clarify the test, i.e. a thorough analysis of at least 5 leukocyte fractions.

This is called. leukogram.

Leukogram - is the number of individual types of white blood cells expressed as a percentage.


Neutrophils are the most numerous of the leukocytes, the so-called. the first line of defense in the body.

Their role is to destroy the triggers of inflammation.

Divided into:

  • rod neutrophils (juvenile),
  • Segmented (mature) neutrophils.
An increase in the number of sticks indicates acute inflammation, and the number of segments indicates long-term, chronic inflammation.

Increased neutrophil count (neutrophilia):

  • acute and chronic inflammation,
  • stress or exercise,
  • poisoning with lead, mercury, arsenic compounds,
  • poisoning with certain drugs (e.g. digitalis),
  • metabolic diseases causing acidosis,
  • some neoplastic diseases,
  • treatment with glucocorticosteroids,
  • physiological occurs in newborns and in the mother in the perinatal period.

Low neutrophil count (neutropenia):

  • some viral infections,
  • some fungal infections,
  • some protozoal infections;
  • agranulocytosis.

Often, when assessing the result of a leukogram examination, one can meet the term: image shift to the left.

It is a change in the proportion between neutrophils with a rod-shaped nucleus and cells with a segmented nucleus.

A left shift of the image indicates an increase in the number of young neutrophils.

It can occur physiologically in newborns and in the perinatal period.

Pathologically, the shift of the image to the left is associated with:

  • the appearance of acute inflammation,
  • the appearance of stress (e.g. after considerable effort),
  • hemorrhages,
  • sometimes with poisoning,
  • leukemia.

Right shift - This is an increased percentage of segmented neutrophils. It can appear in:

  • chronic inflammation;
  • with bone marrow failure (if accompanied by neutropenia).


It is second most abundant in the group of granulocytes.

Like neutrophils, they destroy the triggers of inflammation.

Increase in eosinophils (eosinophilia):

  • parasitic diseases,
  • allergies,
  • adrenal insufficiency,
  • eosinophilic myositis,
  • eosinophilic cecum and colitis,
  • eosinophilic pneumonia in dogs and cats,
  • cancers of the serous membranes, ovaries, bones,
  • after splenectomy (removal of the spleen),
  • certain medications (salicylates, barbiturates, arsenic and phosphorus compounds, some antibiotics),
  • recovery period after infections,
  • in some bitches during heat.

Reduction in eosinophils (eosinopenia):

  • overactive adrenal cortex,
  • treatment with glucocorticosteroids,
  • stress.

Basophils (Basophils)

Increasing the number of basophils (basophilia):

  • chronic hemolytic anemia,
  • diseases in the course of which hypersensitivity reactions occur,
  • states of exhaustion and hunger.


Lymphocytes are cells of the immune system whose role is to recognize factors that are foreign to the body.

Increase in the number of lymphocytes (lymphocytosis):

  • some neoplastic diseases,
  • overactive thyroid gland,
  • adrenal insufficiency,
  • some chronic diseases.

Reduction in the number of lymphocytes (lymphopenia):

  • advanced neoplastic disease,
  • renal and circulatory failure,
  • hepatitis in dogs,
  • FIV infection in cats,
  • feline panleukopenia,
  • nasal,
  • overactive adrenal cortex (increased concentration of glycocosticosteroids).

Monocytes: the largest white blood cells

Increase in monocytes (monocytosis):

  • some infectious diseases,
  • some neoplastic diseases,
  • some blood parasites,
  • overactive adrenal cortex.

Determination of white blood cells - WBC is the number of leukocytes (i.e. the entire population of white blood cells) and the quantitative variation of their individual fractions in a blood smear.

Although white blood cell differentiation is always assessed as a percentage, it should only be interpreted in terms of absolute numbers.

Leukogram data is used to determine whether a disease process is inflammatory or non-inflammatory.

The role of stress in the disease process can also be partially assessed.

A left shift, i.e. the presence of an increased number of immature neutrophils (rods) indicates acute or subacute inflammation.

In dogs and cats, most of the inflammatory processes are accompanied leukocytosis with neutrophilia and possible monocytosis, but leukopenia with neutropenia and shifted to the left (degenerative shift to the left) can be observed with heavy, depressing an inflammatory disease.

Chronic inflammatory diseases are usually of low grade and are therefore characterized by normal or elevated leukocyte counts with mature neutrophilia, no left shift and often monocytosis.

Stress (release of endogenous steroids) or administration of exogenous steroids results in the presence of leukopenia.

So in dogs and cats suffering from chronic stress-related inflammatory diseases, you can expect:

  • leukocytosis with neutrophilia,
  • left shift (regenerative),
  • monocytosis,
  • lymphopenia.

A stress leukogram without accompanying inflammation is usually referred to as mild leukocytosis with mature neutrophilia, bez shift to the left, lymphopenia, eosinopenia and marginal monocytosis.

Suspecting stress in a complete blood count is important in the biochemical panel.

Stress-related physiological increases in glucocorticoids may cause a moderate increase in blood glucose (> 135 mg / dL, but < niż próg nerkowy 180 mg/dl).

Higher than physiological growths (e.g. Cushing's disease, exogenous steroids) may additionally cause a significant increase in alkaline phosphatase or impair the ability of the kidney tubules to concentrate.

Platelets (Thrombocytes, PLT)

Platelets are involved in blood clotting.

Increase in the number of platelets (thrombocytosis, thrombocythemia):

  • after hemorrhages,
  • with iron deficiency,
  • in the course of neoplastic diseases.

Reduction in the number of platelets (thrombocytopenia, thrombocytopenia):

  • bone marrow damage,
  • some viral infections (e.g. canine infectious hepatitis),
  • immune background thrombocytopenia,
  • drugs (sulfonamides and trimethoprim),
  • babesiosis.

The platelet parameters in the hemogram include the assessment of the number of platelets and the assessment of their morphology in the smear.

The most common platelet abnormality in animals is thrombocytopenia.

Thrombocytopenia may be associated with:

  • an immune disease,
  • bone marrow hypoproliferation,
  • involvement of the spleen.

In addition, thrombocytopenia can be a feature of disseminated intravascular coagulation (DIC), a syndrome that is almost always secondary to a severe, deeper systemic disease and that usually causes abnormalities in the biochemical profile.


A coagulogram is a study of blood elements and factors involved in blood clotting.

This test determines:

Bleeding time

This is the time from the moment the skin is injured until the blood flow stops.

It is dependent on the number of platelets and the condition of the blood vessels and, to a lesser extent, on the plasma coagulation factors.

In dogs and cats, the bleeding time should be up to 5 minutes.

Prolongation of bleeding time:

  • coagulation defects,
  • thrombocytopenia,
  • toxic platelet dysfunction,
  • von Willebrand disease.

Clotting time

This is the time from the moment of blood collection to the moment of its clotting in the glass capillary.

In dogs it is up to 13 minutes, in cats up to 9 minutes.

Extending the clotting time:

  • hemorrhagic diathesis,
  • some infectious diseases (e.g. nasal),
  • anemia,
  • liver disease,
  • rat poisoning.

Reduction of the clotting time:

  • intestinal catarrh, diseases with constipation,
  • nephritis,
  • chronic respiratory catarrh,
  • administration of calcium preparations and vitamins C and K,
  • blood or plasma transfusion,
  • disseminated intravascular coagulation (DIC).

Activated Clotting Time (ACT)

Activated clotting time is the time of blood clotting with the addition of an activator.

It is used to control heparin therapy.

ACT it is also used to screen for anticoagulant poisoning.

Norm in dogs up to 95 seconds at 37 ° C (up to 130 seconds at room temperature) and in cats up to 90 seconds at 37 ° C.

Cephalin Time (PTT)

Cephalin time is a measure of the prothrombin activation system and is independent of blood platelets.

It should be 18-30 seconds.

Kaolin-Kephalin Time (APTT)

Kaolin-Kephalin Time is a measure of the activation system prothrombin, after maximum activation of clotting factors (XI and XII).

It is used to screen all clotting factors except factor VII.

It can also be used to monitor response to heparin therapy as well as to diagnose anticoagulant poisoning.

In dogs, it should be up to 11 seconds, in cats up to 15 seconds.

Prothrombin Index (PT)

Prothrombin index is a measure of the prothrombin system, but is independent of most clotting factors (except V, VII, and X) and platelets.

It is a sensitive test for diagnosing anticoagulant poisoning (vitamin K1 deficiency).

In a dog it is 7-10 seconds, at the cat 7-12 seconds.

Thrombin time (TT)

Thrombin time is a measure of the conversion of fibrinogen to fibrin.

It is used to monitor heparin therapy.

In animals with clotting problems, a prolonged thrombin time is suggested by DIC.

In dogs it should last up to 11 seconds, in cats up to 20 seconds.

Antithrombin III (AT III)

Antithrombin III is a globulin produced in the liver that interacts with heparin to inhibit clotting factors.

A lowered level is an early indicator of hypercoagulability, e.g. in the course of:

  • DIC,
  • glomerulonephritis,
  • protein-loving enteropathy.

Elevated levels occur in estrogen-treated patients with mechanical jaundice and vitamin K1 deficiency.

Norma (bad. immunological) - 17-30 mg / dL, bad. Functional - 80-120%.

The concentration of fibrinogen

Fibrinogen is a protein synthesized in the liver which is converted into fibrin, thus participating in the formation of a clot.

Increased fibrinogen concentration occurs with:

  • kidney diseases:
    • nephrotic syndrome,
    • glomerulonephritis,
  • acute phase reactions:
    • inflammation,
    • infectious diseases,
    • major injuries and surgical operations,
  • collagen synthesis disorders,
  • neoplastic diseases.

Lowering the concentration of fibrinogen:

  • liver diseases:
    • acute inflammation,
    • cirrhosis,
    • liver necrosis,
  • disseminated intravascular coagulation syndrome;
  • hemorrhagic diathesis.
In dogs, the norm is 1-5 g / l;. in cats 0.5-3 g / l.

Clot lysis test

The clot lysis test is an indirect screening test for fibrin degradation products.

Premature lysis (breakdown) of the clot suggests increased activity of the fibrinolytic system.

The clot normally breaks up over the course of 8-20 hours. Faster lysis indicates increased fibrin degradation, as is the case with DIC.

Correct disintegration of the clot: > 8 hours. Incorrect lysis: < 8 godzin.

Clot withdrawal

The diluted whole blood clot retraction test is a rapid test for assessing platelet function.

A clot shrinks to 1/3 of its original size when there are enough and properly functioning platelets.

Lack of clot contraction indicates a disturbed platelet function, if platelets are normal.

Platelet dysfunction is often seen with uremia or ingestion aspirin.

Correct clot retraction: < 1 godzina.

Study of D-Dimers

D-dimers are an indicator of intravascular coagulation and occur earlier than fibrin degradation products (FDPs).

They come from cross-linked fibrin.

The norm in dogs and cats: < 0,5 μg/ml or < 0,5 mg/L.

Antiplatelet antibodies

Platelet factor-3 (PF-3) is an indirect test of anti-platelet serum antibodies.

If present, they reduce the clotting time compared to a test performed with normal serum.

This test has been replaced by the direct test.

Platelet-bound immunoglobulin

Platelet-bound immunoglobulin it is the test of choice for the determination of immune thrombocytopenia.

A negative result excludes immune disorders, but a positive result does not differentiate between primary and secondary immune thrombocytopenia (IMT).

Secondary IMT is caused by:

  • live virus vaccines,
  • anxieties,
  • ricketts,
  • viruses.

Factor VIII related antigen

It is used for diagnosis von Willebrand disease.

When the level of this indicator drops less than 30% normal, bleeding occurs despite normal platelet count.

Carriers of this bleeding tendency can be detected by quantifying this factor:

  • < 30% wartości prawidłowej – zwiększone ryzyko krwawienia,
  • < 50% wartości prawidłowej – nosiciele choroby von Willebrand'a.

Fibrin degradation products (FDPs)

Fibrin degradation products they come from the breakdown of fibrin clots when there is too much clot in the body.

This test is used to document disseminated intravascular coagulation (DIC).

Healthy animals do not have FDPs.

Biochemical tests of dog and cat blood serum

Biochemical study

Biochemical testing is defined as the use of multiple blood chemistry determinations to assess the health of individual organs simultaneously.

In addition to standard chemical tests, other parameters are also measured (e.g. hemogram, urine test) for a more accurate and complete picture of the patient's overall health.

In short, the hematology and general urinalysis tests are not part of the biochemical tests, however the latter cannot be accurately interpreted without the total blood count and urinalysis.

Biochemical profiling is a powerful diagnostic and monitoring tool used in sick patients and in those receiving therapy.

It is also an important part of the regular health evaluation of healthy dogs and cats.

While blood chemistry offers exciting potential as a clinical tool, it is not a panacea.

This test will not cure the patient, but will only show the direction of the therapy.

As standard biochemical profiles may contain from 12 to 30 different test results, interpreting this data can be very complicated.

Moreover, the interpretation of results is often "veiled" by the fact that perfectly normal animals may have, and in fact are even expected to have, test results occasionally abnormal.

It is estimated that in a standard panel of 12 chemical analyzes about 46% all healthy patients will have at least one abnormal test result.

Such misstatements are usually related to the way (normal) reference values ​​are determined.

In order to establish normal reference values ​​for a given test, the procedure is performed with samples from a large population of clinically healthy individuals.

Just as healthy subjects may occasionally experience abnormal test results, animals with severe organ disease may have test results that fall within normal reference ranges.

For example:

elevated levels of alanine transaminase (ALT) - an enzyme normally found in the cytoplasm of hepatocytes - has long been recognized as an important indicator of liver disease in dogs.

However, serum ALT levels will only be elevated under certain circumstances, e.g. under conditions where the cytoplasmic membranes of hepatocytes are damaged, which causes the release of cytoplasm from membrane-bound vesicles.

In more chronic liver disease, the properties of the cell membrane may be almost normal.

Additionally, ALT levels reflect the number of hepatocytes with damaged membranes; therefore, pronounced elevations are more often seen in diffuse rather than localized liver disease.

ALT levels will also vary depending on the stage of the organ disease at the time of sampling.

The half-life of this enzyme in the circulation is 2-4 days, therefore, a 2-fold increase in ALT due to acute liver necrosis may result in recovery within one week.

The clinician must be aware that physical changes in one system may cause abnormal values ​​in tests that are used to indicate disease in another system.

For example:

Calcium levels are used primarily as indicators of parathyroid hormone activity. However, serum calcium is partially bound to the albumin filtrate.

Hence, anything that lowers the level of albumin can thereby cause a reduction in blood calcium levels, which may lead to erroneous conclusions about blood calcium levels.

Key points in the interpretation of biochemical test results

  • Never use a single biochemical parameter to assess the health of a specific organ or system.
  • It is important to understand the factors influencing a given test result, such as causes of growth, half-lives of measured parameters, and route of excretion.
  • Always consider the interactions between different organ systems and how this interaction might affect different test results.
  • Only by systematically evaluating the data can misinterpretation and confusion be avoided.

Routine biochemical tests

ALT - alanine aminotransferase / alanine transferase

It is present in large amounts in the cytoplasm of the liver cells of dogs and cats.

This enzyme enters the blood when hepatocytes are damaged or destroyed and circulates in the serum for several days.

This is a very sensitive indicator of active liver injury, but does not indicate a cause or reversibility of the injury.

Increased serum ALT levels indicate recent or ongoing damage to liver cells.

Increasing the minimum level 3 times testifies to severe liver damage over the past 2-5 days.

Increase in activity ALT shows damage or hepatic cell necrosis.

Norm in dogs: 3-50 IU / L Norm in cats: 20-107 IU / L.

Increase in ALT activity from reference values ​​to 200 U / L:

  • liver cancer,
  • inflammation of the pancreas,
  • haemolysis.

Increase in activity from 200-400 U / L:

  • hepatic cholestasis,
  • cirrhosis of the liver (with increased AST values),
  • treatment with high doses of salicylates.

Increase in activity 400-4000 U / L:

  • viral hepatitis;
  • toxic liver damage;
  • circulatory failure.

AST: aspartate aminotransferase

AST is an enzyme related to the mitochondria.

It is found in many tissues in the body, but is especially high in the liver and striated muscle.

Serum AST is elevated with skeletal muscle necrosis and hepatic cell necrosis.

Elevated AST levels with no increase in ALT indicate muscle necrosis.

In liver injury, AST increases more slowly than ALT and indicates a more complete cellular disturbance, as AST "leaks " from cells only with necrosis and not with membrane instability.

Increased serum AST levels suggest muscle necrosis or liver necrosis.

In liver disease, serum AST returns to normal faster than ALT.

Rising levels indicate steady, serious damage to hepatocytes.

The normal plasma half-life is approximately 12 hours in dogs and 2 hours in cats.

The persistence of high, stable serum levels above the 2-3 normal half-lives may be due to:

  • continuous cell damage,
  • increased synthesis in normal hepatic tissue,
  • the formation of macroenzymes.

Hemolysis or lipemia may mildly raise serum AST levels.

Norm in dogs: 1-37 IU / L. Norm in cats: 6-44 IU / L.

Increase in activity from reference values ​​to 200 U / L:

  • cirrhosis,
  • inflammation of the pancreas,
  • haemolysis.

Increase in activity 200-400 U / L:

  • skeletal muscle diseases,
  • chronic hepatitis,
  • surgical procedures,
  • parasites,
  • selenium and vitamin E deficiency.

Increase in activity 400- 4000 U / L:

  • myocardial infarction,
  • viral hepatitis,
  • toxic liver damage,
  • tumors.

The appearance of elevated serum levels of AST in the same way as ALT indicates cell damage, not organ dysfunction.

It is useful in the diagnosis of certain diseases de Ritis index, describing AST / ALT ratio.

The AST value is correct is 1.2 - 1.8.

ALP / AP: alkaline phosphatase

Alkaline phosphatase is present in both the liver and bones.

Elevated serum AP levels indicate increased AP production by liver parenchyma, biliary tract, growing bones, or decreased biliary or urinary excretion.

This enzyme is induced by cholestasis and in dogs by corticosteroids or anticonvulsants.

Increased activity phosphatase does not suggest liver or bone necrosis.

The most important causes of increased AP levels in the blood serum are liver cholestasis or excessive supply of exogenous glucocorticosteroids.

The AP level rises after an episode acute pancreatitis because secondary bile duct inflammation.

It also increases if liver disease causes disturbances in the hepatobiliary architecture with local disturbances in bile flow.

Cats have less phosphatase than dogs and the kidneys quickly excrete little excess.

Any increased AP activity in cats is significant and suggests cholestasis.

Normal values ​​for puppies and kittens are higher than for adults due to active bone growth.

Diseases that cause bone remodeling in adults produce small gains (less than twice the normal).

Persistent elevations in AP activity not related to ongoing disease may be associated with a decrease in clearance following diseases such as:

  • kidney failure,
  • cirrhosis,
  • creating macroenzymes.

Liver cholestasis and the excessive supply of exogenous glucocorticoids are the most important causes of the increase in AP in dogs

Norm in dogs: 20-155 IU / L. Norm in cats: 23-107 IU / L.

Increase in AT activity:

  • congestive jaundice,
  • viral and toxic hepatitis,
  • cirrhosis,
  • myeloid leukemia,
  • bone tumors,
  • osteomalacia,
  • rickets,
  • after treatment with glucocorticoids,
  • overactive adrenal cortex in dogs,
  • physiologically - pregnancy, growth period.

CIALP: Corticosteroid-induced Alkaline Phosphatase

Corticosteroid-induced alkaline phosphatase is an isoenzyme that increases the total phosphatase in the dog's serum.

It has a prognostic value in diagnosis hyperadrenocorticism (overactive adrenal cortex).

The lack of this isoenzyme in the blood makes the diagnosis of hyperadrenocorticism unlikely.

Conversely, high levels may be present with additional adrenal disease, so this is not a good screening test for adrenal disease.

ACP: acid phosphatase

Standard in dogs: 30-120 U / L, standard in cats: 20-63 U / L

Increase in ACP activity:

  • prostate cancer,
  • malignant bone tumors,
  • haemolysis,
  • destroyed platelets,
  • primary hyperparathyroidism.

GGT (γ- GGT): gamma glutamyltransferase

GGT is an induced liver enzyme that indicates disease in the portal biliary system.

An increase in GGT activity accompanies an increase in AP, but GGT is not found in bone.

Glucocorticoids and cholestasis induce GGT production.

In cats, the activity of this enzyme tends to be greater than the activity of AP in cholestasis.

Increased GGT levels indicate liver disease with cholestasis or excess cortisol (in dogs).

Normal in dogs: 5-25 IU / l, normal in cats: < 5 IU/L.

The increase in GGT activity can be observed with:

  • cholestasis inside - and extrahepatic,
  • acute and chronic pancreatitis,
  • acute hepatitis,
  • colonic ulcer disease,
  • after treatment with glucocorticoids in dogs.


Increased baseline blood ammonia levels or persistent high blood ammonia levels following oral administration of ammonium chloride (available as a urine acidifier) ​​indicate liver failure.

This test is helpful in evaluating animals from:

  • chronic weight loss,
  • abnormal symptoms from the central nervous system,
  • small liver.

Abnormalities correlate with tests on serum bile acids.

Ammonia levels increase:

  • congenital and acquired hepatic leaks,
  • biliary obstruction,
  • biliary hepatitis,
  • jaundice.

Bump Test Protocol:

  • administration of ammonium chloride in the amount of 100 mg / kg orally,
  • taking a blood sample 30-45 minutes after administration of ammonium chloride.

The increase in ammonia indicates:

  • liver failure,
  • possible with a high-protein diet,
  • gastrointestinal hemorrhages.
Norm in dogs:


Amylase is released into the blood and into the peritoneal cavity:

  • inflammation of the pancreas,
  • pancreatic necrosis,
  • pancreatic duct obstruction.

This raises the blood serum amylase levels 2-3 times.

Increased absorption due to enteritis and decreased renal excretion gently increase serum amylase activity.

When associated with abdominal pain, increased serum amylase activity suggests acute pancreatitis.

However, since many cats with acute pancreatitis have amylase within the reference standard, a better test to detect it is fPL test.

Normal in dogs: 388-1800 IU / L, normal in cats: 433-1248 IU / L.

An increase in amylase activity may indicate:

  • acute pancreatitis,
  • bowel obstruction,
  • ketoacidosis in diabetes,
  • kidney failure,
  • overactive adrenal cortex,
  • obstruction of the salivary glands.

The decrease in amylase activity is observed with:

  • pancreatic necrosis,
  • extensive burns,
  • poisoning with heavy metals.


Lipase is a pancreatic enzyme that is normally secreted into the duodenum when food is digested.

It can be pathologically activated in the pancreas by lipemia or trauma to the pancreas.

Pancreatic necrosis sometimes it raises serum lipase levels 2-7 times within 48 hours.

Lipase activity also increases with increased absorption as a result inflammation of the small intestines and with reduced secretion at kidney failure.

Following pancreatic damage, serum lipase levels remain elevated for longer than amylase levels.

Kidney failure can raise lipase levels, but this is not related to pancreatitis.

Normal in dogs: 268-1769 IU / L, normal in cats: 157-1715 IU / L.

Increase in lipase activity:

  • acute pancreatitis,
  • pancreatic tumors,
  • kidney disease,
  • bowel obstruction.

Heparin stimulation test for lipoprotein lipase

This test differentiates postprandial lipemia from pathological lipemia.

Lipoprotein lipase deficiency can occur in:

  • diabetes,
  • acute pancreatitis,
  • hypothyroidism,
  • excess of glucocorticoids,
  • idiopathic lipoproteinemia in schoonchers.

Study protocol:

  • If the blood is lipemic:
    1. heparin should be administered intravenously at a dose of 200 IU / kg m.c.
    2. a blood sample is taken after 15 minutes.
    3. the purification of turbidity (fat) in the collected blood sample is observed
  • Interpretation:
    1. cleansing means normal lipoprotein lipase and postprandial hyperlipidemia,
    2. lack of cleansing indicates pathological lipemia resulting from lipoprotein lipase deficiency.

Bile acids

Serum bile acid testing is used for the evaluation of the liver's excretory system.

They are helpful in determining the cause of chronic weight loss, abnormal symptoms from the central nervous system and small liver.

It is investigating 2 blood samples - on an empty stomach and 2 hours after a meal.

Congenital and acquired hepatic leakages, bile duct obstruction, biliary hepatitis, and jaundice increase serum bile acid levels.

Occasionally, fasting levels of bile acids are higher than postprandial.

It is caused by the stimulation of the gallbladder by gastric juice that passes into the intestines.

If any of the values ​​exceed the high postprandial values, hepatic anastomosis is strongly suggested.

In young animals with seizures or convulsions, but without apparent liver disease, bile acids are used to check for congenital macroscopic and microscopic vascular leakage.

In animals with persistently elevated levels of ALT or other indicators of hepatobiliary disease, abnormally high levels of bile acids indicate anastomoses, due to increased resistance to hepatic portal blood flow due to intrahepatic disease.

This is a good indicator of active liver disease.

Low levels of bile acids with high levels of alkaline phosphatase may be more indicative of steroid hepatopathy than inflammation of the bile ducts.

Increased bile acid levels along with increased alkaline phosphatase levels occur in non-steroidal hepatitis.

Norm in dogs: fasting (12-hour fast): < 30 μmol/L, po posiłku (2 godziny): 55 μmol/L.

Norm in cats: fasting (12-hour fast): < 25 μmol/L, po posiłku: 35 μmol/L.

Increasing the concentration of bile acids:

  • primary and secondary liver damage,
  • intra- and extrahepatic cholestasis,
  • portal anastomosis, collateral.

Lowering bile acid levels:

  • retention of contents in the intestines,
  • malabsorption syndrome.


Bilirubin it is derived from hemoglobin catabolism and circulates in conjugated and unconjugated forms.

Any bilirubin in urine is its conjugate form.

Unconjugated bilirubin is insoluble in water and does not pass into the urine.

Increased levels of unconjugated bilirubin in combination with anemia suggest hemolysis.

Increased total bilirubin levels indicate liver disease or hemolytic disease.

Normal in dogs: total bilirubin: 0-0.2 mg / dL or 0-3.4 μmol / L, conjugated bilirubin: 0-0.02 mg / dL or 0-0.3 μmol / L. Normal in cats: total bilirubin: 0-0.4 mg / dL or 0-6.8 μmol / L, conjugated bilirubin: 0-0.1 mg / dL or 0-1.7 μmol / L.

Increased bilirubin levels:

  • haemolytic jaundice (increased breakdown of red blood cells) - there is an increase in the concentration of indirect bilirubin;
  • mechanical jaundice (obstructed outflow of bile from the liver) - there is an increase in the concentration of direct bilirubin;
  • parenchymal jaundice (damage to liver cells resulting in impaired excretory function). There is an increase in the concentration of direct and indirect bilirubin.


Cholesterol is primarily produced in the liver and excreted in the bile.

Hypercholesterolaemia (excess cholesterol) occurs in:

  • obstructive biliary tract diseases,
  • hypothyroidism,
  • overactive adrenal cortex,
  • acute inflammation of the kidneys,
  • nephrotic syndrome,
  • primary lipid disorders.

Liver cell disease, diabetes and anorexia reduce the production of cholesterol and limit its level in the serum.

Normal in dogs: 127.7-360 mg / dl or 3.3-9.3 mmol / L, normal in cats: 77.4-201.2 mg / dl or 2.0-5.2 mmol / L.

Cholesterol is not a diagnostic test when done alone, but it complements other tests.

Raising the concentration (hypercholesterolaemia):

  • nephrosis,
  • congestive jaundice,
  • diabetes,
  • hypothyroidism in dogs,
  • overactive adrenal cortex,
  • a diet too high in fat,
  • nephrotic syndrome,
  • acute renal failure.

Lowering the concentration (hypocholesterolaemia):

  • pancreatic insufficiency,
  • liver diseases (cirrhosis, necrosis, toxic damage),
  • overactive thyroid gland in dogs,
  • anemia.


Increased levels of triglycerides in the blood (hyperlipidemia) causes its lipemic (milky) appearance.

This may be normal up to 12 hours after a meal (postprandial hyperlipidemia) and is usually "cleared" after intravenous heparin.

If fasting hypertriglyceridemia also persists, it is usually caused by:

  • diabetes,
  • Hypothyroidism,
  • excess cortisol,
  • cholestasis,
  • sometimes it is idiopathic in some Miniature Schnauzers.

Hyperlipidemia is both a cause and a consequence of acute pancreatitis.

Normal in dogs: 17.7-115.1 mg / dl or 0.2-1.3 mmol / L, normal in cats: 17.7-159.4 mg / dl or 0.2-1.8 mmol / L.

Increasing the concentration:

  • diabetes,
  • inflammation of the pancreas,
  • nephrosis,
  • obstruction of the bile ducts.

Lipoprotein electrophoresis

Unexplained persistent fasting hyperlipidemia can be investigated by lipid-bearing protein electrophoresis.

Electrophoresis can be used to classify lipoproteins, but does not provide any information about the underlying cause of hyperlipidemia.


  • Chylomicrons - contain triglycerides derived from dietary fat and are synthesized in the intestinal mucosa.
  • Very low density lipoproteins (VLDL) are rich in triglycerides and are synthesized in the liver.
  • Low-density lipoprotein (LDL) is high in cholesterol. They are formed from VLDL by removing triglycerides by lipoproein lipase.
  • High-density lipoproteins (HDL) - are the main carriers of cholesterol in dogs. They are synthesized in the liver

BUN / SUN: Blood urea nitrogen

The increased level of nitrogenous products of metabolism in the blood is called azotaemia.

When the growth is renal in origin, or when the accumulation of nitrogenous waste products causes clinical symptoms, the condition is called uraemia.

The increase in BUN levels may be due to:

  • prerenal,
  • kidney,
  • postoperative.

Common prerenal causes include:

  • heart disease,
  • hyperadrenocorticism,
  • dehydration,
  • shock.

Common non-degenerative causes are:

  • obstruction of the urethra,
  • rupture of the bladder,
  • perforation of the urethra.

Glomerular, tubular, or interstitial kidney disease that causes increased BUN indicates that over 70% of nephrons it is non-functional.

Urinalysis with specific gravity and sedimentation can be used to differentiate prerenal azotaemia from renal background azota.

BUN levels are lowered with prolonged starvation or chronic liver disease.

An increase in BUN indicates azotaemia or uremia.

Normal in dogs: 10-25 mg / dl or 6 U / L, normal in cats: 10-30 mg / dl or < 5 U/l.


Normal in dogs: 20-45 mg / dl or 3.32-7.47 mmol / l, normal in cats: 25-70 mg / dl or 4.15-11.62 mol / l.

Increasing the concentration:

Prerenal causes:

  • dehydration,
  • diseases of the cardiovascular system,
  • hemorrhage in the digestive tract,
  • increased catabolism (fever, muscle damage),
  • post-traumatic stress,
  • high-protein diet.

Kidney causes:

  • pyelonephritis,
  • acute and chronic glomerulonephritis,
  • cirrhosis of the kidneys,
  • nephrosis.

Non-renal causes:

  • nephrolithiasis and bladder stones.

Lowering the concentration

  • severe liver damage,
  • after glucose infusion.


Creatinine is a non-protein nitrogen product of muscle metabolism.

Diet and protein catabolism have a much smaller effect on creatinine levels than on BUN levels.

As with BUN, serum creatinine levels are elevated by conditions that limit glomerular filtration.

Isosthenuria (urine specific gravity 1.010 +/- 0.02) suggests a renal cause, but higher specific gravity suggests prerenal or atrophic causes.

Since the rate of urinary creatinine excretion is constant, the level of creatinine in the urine can be used to quantify other hormones or proteins excreted.

Normal in dogs: 1-1.7 mg / dl or 88.4-150.3 μmol / L, normal in cats: 1-1.8 mg / dl or 88.4 - 159.1 μmol / L.

Increasing the concentration:

  • increased production after exercise,
  • reduced excretion (renal failure, drugs with nephrotoxic side effects, poisoning with organic and inorganic compounds).

Lowering the concentration:

  • starvation,
  • glucocorticosteroids.

BUN / Creatinine ratio

Decreasing glomerular filtration rate usually increases BUN and creatinine levels in equal proportions.

Sometimes, however, there is a disproportionate increase in the ratio of BUN to creatinine.

A ratio greater than 20: 1 suggests prerenal nitrogenemia.

In healthy animals, the ratio of BUN to creatinine is normal greater than 5.

When the liver fails to convert ammonia to urea, this ratio may drop.

A low ratio is a strong suggestion of chronic liver failure, especially when other symptoms of liver dysfunction are present.

To confirm the poor conversion of ammonia, perform an ammonia tolerance test.

Normal in dogs and cats:> 5-20.


In dogs, significant, persistent hyperglycaemia (high blood sugar) is usually caused by diabetes.

Endogenous adrenaline secretion and postprandial sampling may result in transient hyperglycaemia.

In cats, diabetes mellitus, epinephrine release, and systemic disease can produce significant and usually permanent hyperglycaemia.

Exogenous glucocorticosteroids and progestogens cause mild hyperglycemia and delay glucose consumption.

Muscle activity (convulsions or chills) also results in a transient increase in blood glucose levels.

Hypoglycaemia can be caused by:

  • insulin-secreting pancreatic tumors,
  • starvation,
  • adrenal insufficiency,
  • hypopituitarism,
  • shock,
  • tumors not originating in the pancreas,
  • strong effort .

The most common cause of low glucose levels is improper handling of the blood sample.

Increase in blood glucose occurs with stress and diabetes.

The most common cause of lowering glucose is a laboratory error.

Normal in dogs: 70-120 mg / dl or 3.9 - 6.7 mmol / l, normal in cats: 100-130 mg / dl or 5.6-7.3 mmol / l.

Raising the concentration (hyperglycaemia):

  • diabetes,
  • nephritis,
  • inflammation of the pancreas,
  • dehydration,
  • excess cortisol (iatrogenic),
  • hyperfunction of the adrenal cortex and the adrenal medulla,
  • an overactive pituitary gland,
  • overactive thyroid gland,
  • after a meal (physiologically),
  • The Polish Lowland Sheepdog has a tendency to elevate glucose levels,
  • in cats under stress.

Lowering the concentration (hypoglycaemia):

  • islets of Langerhans overactive,
  • kidney failure,
  • adrenal insufficiency,
  • severe anemia,
  • toxic liver damage,
  • cirrhosis,
  • prolonged physical exertion,
  • hunger or malabsorption,
  • puppy hypoglycemic syndrome,
  • physiological lowering during pregnancy and lactation,
  • glycogen storage diseases,
  • shock.

Glucose tolerance test

The glucose tolerance test is indicated for patients with mild hyperglycaemia (glucose 125-150 mg / dL).

It is used to detect pre-diabetes and insulinoma.

Glucose Tolerance Test - Test Protocol:

  1. A blood sample is taken from a starved patient.
  2. After a 24-hour fast, 50% glucose is administered intravenously at a dose of 0.5 ml / kg m.c.
  3. Blood samples are taken every 30 minutes for 3 hours after glucose administration.


  • Normal - blood glucose levels return to normal within 60-90 minutes after administration of glucose
  • Abnormally high glucose levels. High glucose levels 90 minutes after injection may indicate hyperadrenocorticism, diabetes, or severe liver disease.
  • An abnormally low post-injection glucose level may indicate isulinoma. In this situation, the sample insulin / glucose ratio must be determined to detect insulinoma.
  • A persistent elevation of glucose indicates pre-diabetes, an excess of glucocorticosteroids.
  • A sharp drop in glucose indicates excess insulin

Fructosamine in the monitoring of hypoproteinemia

Fructosamine is primarily albumin bound to glucose through the glycosylation process.

The fructosamine level depends on the average blood glucose concentration and the age of the albumin molecule (viability 1-2 weeks).

Since albumin becomes glycosylated during its lifetime in the serum, fructosamine can be used to determine the age of circulating albumin.

Concomitant hypoalbuminaemia with normal serum fructosamine levels indicates ongoing hypoalbuminaemia less than 1 week.

Concomitant occurrence of hypoalbuminaemia with lowered fructosamine levels indicates persistent persistent hypoalbuminaemia more than 1 week.

Concomitant normal albumin levels with lowered fructosamine levels indicate improvement after either hypoalbuminaemia or hypoglycemia.

Dog's norm 258-343 μmol / L, cat's norm: 175-400 μmol / L.

Fructosamine in monitoring diabetes

The concentration of fructosamine is proportional to the blood glucose level throughout the duration of the measured glycosylated protein (e.g. 1-2 weeks for cat and dog albumin).

Therefore, the serum fructosamine concentration provides an estimate of the mean blood glucose concentration in a matter of weeks.

Serum fructosamine levels can be used to monitor glycemic control in diabetic dogs and cats.

Fructosamine levels better reflect the metabolic control of diabetics than occasional blood glucose measurements.

In screening for diabetes mellitus, normal serum fructosamine levels in hyperglycemic animals preclude the diagnosis of diabetes mellitus.

Normal in dogs: 258-343 μmol / L, well-regulated diabetes 600 μmol / L.

Standard in cats: 175-400 μmol / L, well-regulated diabetes: 600 μmol / L.

Total Protein (TP)

Total plasma protein content can be determined using both refractometer, what chemical methods.

In hematology, usually measured with a refractometer.

Plasma protein is a conglomerate of over 200 protein fractions, including:

  • albumin,
  • alpha globulins (such as haptoglobin),
  • beta globulins (such as transferrin, hemopexin),
  • fibrinogen,
  • all classes of immunoglobulins.

Since the protein level is a fairly crude estimate of changes in plasma protein, only basic and general interpretations are possible.

Elevated levels of total protein are most often associated with either dehydration, or with chronic antigenic stimulation with hypergammaglobulinemia.

Increasing the total protein content affects the interpretation of other laboratory data, e.g.:

elevated TP levels in combination with elevated hematocrit suggests that the animal is likely to be dehydrated as a result relative polycythemia.

If the patient is adequately hydrated, the hematocrit will most likely return to normal.

On the other hand, elevated levels of total protein combined with low hematocrit are alarming as dehydration can mask a more severe anemia.

When TP is elevated secondary to dehydration, other biochemical changes should be taken into account, e.g.:

electrolyte levels should be higher due to sample concentration.

Prerenal azotaemia secondary to hypovolemia is often present, and is characterized by mild to moderate increases in blood urea nitrogen and creatinine.

If renal tubular function is normal, an increase in urine specific gravity is expected.

Decreased levels of total protein (hypoproteinemia) are also very important and further evaluation of individual organs and systems is necessary.

Hypoproteinaemia may be due to:

  • proteinaceous enteropathy (intestinal disease),
  • proteinaceous nephropathy (kidney disease),
  • reduced protein production by the liver,
  • from severe anemia due to blood loss.

The form of hypoproteinaemia, as determined by testing total protein and albumin, can be very helpful in differentiating the underlying etiology.

Protein enteropathy and blood loss are usually characterized by decreased levels of all protein fractions (total protein, albumin and globulin).

Protein-related nephropathy is often characterized by hypoproteinemia low in albumin and normal globulin.

Proteinuria (that is, the presence of protein in the urine) is often detected with urine test strips.

Decreased hepatic protein production is most often characterized by hypoproteinemia with hypoalbuminaemia and usually by hypergammaglobulinemia.

Normal in dogs: 5.5-7.8 g / dl or 55-78 g / L, normal in cats: 5.5-7.9 g / dl or 55-79 g / L.

Increasing the concentration (hyperproteinemia):

  • dehydration;
  • neoplastic diseases (lymphoma, myeloma, plasmacytoma);
  • chronic inflammation;
  • liver protein-forming hyperactivity;
  • ehrlichiosis;
  • FIP in cats;
  • heartworms;
  • lymphocytic cholangitis;
  • purulent cholangitis;
  • strenuous exercise - can increase protein levels by 10%.

Lowering the concentration (hypoproteinaemia):

  • impaired absorption in the intestines;
  • abnormal digestion;
  • parasitic diseases;
  • bacterial enteritis;
  • intestinal histoplasmosis;
  • diarrhea from the small intestines;
  • nutritional (protein) deficiencies;
  • extensive wounds and burns;
  • liver atrophy and fibrosis;
  • cirrhosis;
  • chronic bleeding;
  • overactive thyroid gland;
  • peritonitis (with the exception of feline infectious peritonitis when the protein increases);
  • kidney diseases associated with proteinuria;
  • protein-loving enteropathies;
  • overhydration;
  • conditions causing increased breakdown of protein (fever);
  • starvation;
  • increased protein requirements (pregnancy, lactation).


Albumin are plasma proteins that:

  • affect the osmotic pressure,
  • bind calcium,
  • transport bile acids,
  • they transport a lot of drugs.

The level of serum albumin is reduced by:

  • starvation,
  • internal parasite infestations,
  • chronic diseases with a malabsorption of nutrients,
  • chronic liver disease,
  • exudative enteritis,
  • glomerulonephritis.

Hypoalbuminemia (decreased albumin levels) with normal serum globulin levels suggest decreased albumin production, increased loss or binding.

If your albumin and globulin levels are both low, the likely causes may be:

  • haemorrhage,
  • exudation,
  • blood thinning.

Severe dehydration may increase the serum albumin levels.

Increased albumin levels may suggest dehydration.

Dog's norm: 33-56 g / l, cat's norm: 27-39 g / l.

Increased albumin concentration (hyperalbuminaemia):

  • dehydration,
  • FIP.

Low albumin levels (hypoalbuminaemia):

  • malnutrition,
  • absorption disorders,
  • enteritis,
  • glomerulonephritis,
  • nephrosis,
  • injuries and burns.


Serum globulin levels are usually estimated from total serum protein and albumin.

If globulin levels are elevated, protein electrophoresis can determine if the increase is attributable inflammation or cancer formation.

Inflammation and certain diseases (infectious peritonitis in cats, Ehrlichiosis in dogs) cause polyclonal gammopathies.

Disorders of lymphocytes and plasma cells (lymphoma, multiple myeloma) cause narrow-peak monoclonal gammopathies.

Significant hyperglobulinemia can cause problems due to increased serum viscosity.

Normal in dogs: 2-4 g / dl or 20-40 g / L, normal in cats: 2-5 g / dl or 20-50 g / L.

Alpha globulin

Normal in dogs: 8-23 g / l, normal in cats: 13-45 g / l.

Increase in alpha globulin levels (alpha hyperglobulinemia):

  • end of pregnancy,
  • acute inflammation.

Lowering concentration (alpha hypoglobulinemia):

  • liver disease,
  • kidney disease,
  • malignant tumors,
  • collagenosis.

Beta globulin

Normal in dogs: 15-24 g / l, normal in cats: 4-18 g / l.

Increased levels of beta globulin (beta hyperglobulinemia):

  • Hypothyroidism,
  • chronic inflammation.

Lowering beta globulin levels (beta hypogammaglobulinaemia):

  • after operations,
  • hemolytic anemia,
  • coagulation disorders,
  • haemophilia,
  • autoimmune diseases.

Gamma globulin

Normal in dogs: 8-17 g / l, normal in cats: 5-10 g / l.

Increase in gamma globulin levels (gamma hyperglobulinemia):

  • infections,
  • liver disease,
  • autoimmune diseases.

Gamma globulin decreased (gamma hypoglobulinemia):

  • nephrotic syndrome,
  • lymphocytic leukemias,
  • deficiency and lack of beta globulin,
  • immunosuppression (with long-term therapy with glucocorticosteroids, hyperadrenocorticism).

Viscosity test for hyperproteinemia

Increased serum viscosity indicates hyperglobulinemia and possible gammopathy.

Standard: 3.

Fibrinogen and acute phase proteins

Serum fibrinogen and acute phase proteins are increased by:

  • inflammation,
  • putrefactive decomposition,
  • early pregnancy (28-37 days in dogs),
  • liver disease,
  • tumor,
  • major surgery,
  • disseminated intravascular coagulation (DIC).
Normal in dogs: 100-400 mg / dl, normal in cats: 110-400 mg / dl.

C-reactive protein (CRP)

Level increase:

  • especially acute bacterial infections;,
  • exacerbation of chronic infections,
  • myocardial infarction,
  • malignant tumors.

Creatine Kinase (CK / CPK)

It is also called creatine phosphokinase. It is present in high concentration in:

  • central nervous system,
  • striated muscles,
  • the heart muscle,
  • bladder in cats.

Serum kinase activity is increased by:

  • muscle injuries,
  • intramuscular injections,
  • myositis,
  • occasional damage to the central nervous system.

Increased serum CK levels correspond to an increase in AST activity in muscle necrosis.

Normal in dogs: 25-467 IU / l, normal in cats: 49-688 IU / L.

An increase in creatine kinase activity may suggest:

  • injuries of muscle tissue,
  • myositis (infectious, immune, hormonal),
  • progressive muscle degeneration,
  • heavy physical exertion,
  • intramuscular injections,
  • tetanus,
  • shock,
  • bladder obstruction (in cats),
  • poisoning (e.g. strychnine, carbon monoxide).

Lactate dehydrogenase (LD, LDH)

Used in the diagnosis of muscle or liver diseases.

It is found in all tissues, but especially in muscles, liver and red blood cells.

The increase in the level is noticeable in the following diseases:

  • skeletal muscles,
  • the heart muscle,
  • hepatopathies,
  • cell necrosis,
  • malignant tumors.

Norm in a dog: 105-1683 U / l, norm in a cat: 161-1051 U / l.

Increased lactate dehydrogenalase activity:

  • liver disease,
  • hemolytic anemia,
  • leukemia,
  • skeletal muscle diseases,
  • pneumonia,
  • myocardial infarction,
  • prolonged stress,
  • haemolysis.

Uric acid

The determination of uric acid is used in diagnosis Bronzing Syndrome in Dalmatians and urolithiasis.

In dogs (except Dalmatians), uric acid is metabolized to allantoin in the liver, so its levels are less than 1 mg / dL, and the diurnal secretion of urates < 100 mg.

Dalmatians have a uric acid level of approx. 2 mg / dL; excretion: 400-600 mg urate / day.

Norms in dogs: 0.2-0.9 mg / dl or 0 - 0.50 mmol / l, norms in cats: 0-1.9 mg / dl or 0-0.11 mmol / l.

Increase in uric acid levels:

  • glomerulonephritis,
  • obstruction of the urinary tract,
  • neoplastic diseases, especially leukemia,
  • some liver diseases,
  • starvation.

Lowering uric acid levels:

  • impaired resorptive function of the renal tubules.

Lactic acid

It is formed in the tissues (muscles) through the anaerobic breakdown of glucose.

Norms in dogs: 1.11-3.89 mmol / l, norms in cats: 1.11 - 8.33 mmol / l.

Increasing the concentration of lactic acid:

  • insufficient oxygen supply to tissues,
  • metabolic acidosis,
  • anemia,
  • diabetes.


Makroenzymes are complexes of serum enzymes with proteins with a higher molecular weight and a longer plasma half-life than the normal enzyme.

The presence of macroenzymes is suggested when serum enzyme activity is unrelated to symptoms.

These may explain the persistence of the enzyme in controlling liver or pancreatic disease.

Macroenzymes can cause diagnostic errors and unnecessary tests or invasive procedures.

Functional tests of the adrenal glands

Functional tests of the adrenal glands

Determination of ACTH

An ACTH test can determine the cause of an overactive adrenal cortex.

Normal or high serum ACTH levels with high cortisol levels indicate a tumor in the pituitary gland or a defect in the negative feedback mechanism.

Low ACTH levels with high serum cortisol levels suggest a primary adrenal problem.

Normal values: 20-40 ng / L

In dogs with high serum cortisol levels:

  • ACTH> 40 ng / L suggests pituitary cancer;
  • ACTH < 20 ng/L mocno sugeruje nowotwór nadnerczy;
  • ACTH 20-40 ng / L - inconclusive result.

Acth stimulation test

Most animals with pituitary dependent hyperadrenocorticism overreact to ACTH stimulation.

Animals with adrenal tumor induced hyperadrenocorticism do not respond well to ACTH stimulation, however blood cortisol levels are markedly increased.

Animals with adrenal insufficiency resulting from primary or secondary (iatrogenic) insufficiency of the adrenal cortex do not respond to ACTH stimulation.

Increased cortisol levels following ACTH stimulation are associated with an overactive adrenal cortex.

Decreased cortisol levels following ACTH stimulation are associated with adrenal insufficiency.

Interpretation of results: cortisol level (after ACTH stimulation):

  • Cats:
    • < 5 μg/dl – hipoadrenokortycyzm,
    • 6-12 μg / dl - the norm,
    • 13-16 μg / dl probable hyperadrenocorticism,
    • 16 μg / dL - usually a pituitary tumor.
  • Dogs:
    • < 5 μg/dl – hipoadrenokortycyzm,
    • 6-18 μg / dl - the norm,
    • 18-24 μg / dl - probable hyperadrenocorticism,
    • > 24 μg / dL - usually a pituitary tumor.

Combined acth stimulation test with dexamethasone inhibition test

The ACTH stimulation test and the dexamethasone inhibition test can be done the same day.

It starts with a high dose of dexamethasone (0.1 mg / kg m.c.), a blood sample is taken after 2 hours.

Immediately after the collection, ACTH should be administered intramuscularly, and then blood samples are taken after 30 and 60 minutes.

Normal cortisol levels in dogs:

  • < 1,5 μg/dl po zahamowaniu dexametazonem,

Values ​​greater than those listed suggest hyperadrenocorticism.

Dexamethasone inhibition test

Pituitary ACTH regulates cortisol secretion through hypothalamic feedback.

High levels of endogenous cortisol or administration of dexamethasone inhibit ACTH secretion.

In animals with high serum cortisol levels, caused by stress or a pituitary tumor, injection of dexamethasone will reduce cortisol levels.

In adrenal tumors, the injection of the steroid will not suppress the secretion of cortisol and it will remain high in the serum.

Low-dose dexamethasone inhibition test:

This test helps to differentiate the cortisol levels raised by stress or chronic disease from those raised by spontaneous hyperadrenocorticism.

This test is more sensitive than the ACTH stimulation test as it inhibits levels that result from chronic stress.

Cortisol levels in animals with pituitary or adrenal tumors are usually resistant to inhibition with low doses of dexamethasone.

Normal cortisol levels after administration of dexamethasone in dogs and cats are < 1 μg/dl.

Cortisol levels that indicate an overactive adrenal cortex: > 2 μg / dL.

In some dogs with pituitary dependent hyperadrenocorticism, the decline in cortisol is transient and occurs 2 to 4 hours after injection.

Levels return to resting values ​​6-8 hours after injection.

Animals that only partially inhibit cortisol should be tested for inhibition of high doses of dexamethasone.

High-dose dexamethasone inhibition test

This test is used to distinguish between a pituitary tumor and a tumor of the adrenal gland.

In animals with a tumor of the adrenal gland, dexamethasone will not suppress cortisol levels.

In most animals with pituitary tumors, serum cortisol levels are reduced by at least 50%:

  • Cortisol level < 50% wyjściowego stężenia – guz przysadki
  • Cortisol level> 50% of the starting concentration - adrenal tumor.


Angiotensin and ACTH stimulate the secretion of aldosterone, the leading mineralocorticoid of the adrenal cortex.

In most cases, aldosterone deficiency is indicated by low sodium, high potassium, and a Na / K ratio < 23.

Aldosterone levels can be assessed following ACTH stimulation.

Aldosterone levels following ACTH injection should be at least 2 times the resting value, unless the resting value is in the high-normal range.

  • Normal aldosterone levels before ACTH administration - 5-345 pg / ml.
  • 1 hour after the injection of ACTH - 91-634 pg / ml.
  • 2 hours after the injection of ACTH - 71-758 pg / ml.

The correct answer is to double the baseline aldosterone level unless the pre-ACTH level is within high reference levels.

Cortisol: an indirect test

Insufficient cortisol levels are suggested by:

  • neutropenia,
  • lymphocytosis,
  • eosinophilia

To confirm this, the adrenal response to ACTH should be indirectly assessed by analysis of neutrophils, lymphocytes and eosinophils before and 1-4 hours after intramuscular ACTH administration.

If the ACTH injection increases the number of neutrophils and reduces the number of lymphocytes and eosinophils, the adrenal function is usually normal.

Persistent lymphocytosis and eosinophilia suggest adrenal medullary insufficiency and should be reviewed by assessing blood cortisol levels.

The correct answer is > 30% increase in the ratio of neutrophils / lymphocytes and 50% lowering the number of eosinophils.

Serum cortisol

The blood cortisol level can be measured when there is a suspicion of overactive or underactive adrenal cortex.

Stimulation or inhibition tests are usually necessary as there is a significant "overlap" of levels between healthy dogs and those with adrenal gland disease.

As a result of hospitalization or other stress, basal cortisol levels may falsely rise and an ACTH stimulation test or dexamethasone inhibition test gives more reliable results.

Normal in dogs: 0.5-4 μg / dl or 28-110 nmol / L, normal in cats: 1-4 μg / dl or 48 - 110 nmol / L.

An increase in cortisol suggests stress or an overactive adrenal gland.

A drop in cortisol indicates adrenal insufficiency.

Dog and cat thyroid function tests

Dog and cat thyroid function tests

Over the years, many tests for diagnosing hypothyroidism have been developed.

fT4: free T4

It is the part that acts on the pituitary gland through negative feedback.

It most accurately reflects the functions of the thyroid gland, but does not provide any diagnostic advantage over the T4 test.

Normal in dogs: 1-2 ng / dl or 79-158 pmol / L, normal in cats: 1-2.5 ng / dl or 79-198 pmol / L.

Reverse T3

Reverse triiodothyronine (rT3) is the inactive form of T3.

The main application of rT3 is in the diagnosis of hypothyroidism for reasons not related to the thyroid gland.

In various diseases, T3 levels decline due to the transition from T3 to rT3.

  • When the levels of T4, T3, and rT3 are low, the animal becomes hypothyroid.
  • When serum T4 and T3 levels are low but rT3 levels are high, the cause is a non-thyroid related disease.

This test is very rarely used.

Normal in dogs: 19-45 ng / dl.


Assessing triiodothyronine levels is rarely helpful in diagnosing thyroid dysfunction.

Dogs with high T3 levels (> 250 ng / dL) are likely to have anti-thyroid antibodies and may show clinical signs of hypothyroidism.

For therapy monitoring, blood should be taken 3 hours after T3 administration and 4-8 hours after T4 administration.

Normal in dogs: 100-200 ng / dl or 1.5-3 nmol / L, normal in cats: 75-150 ng / dl or 1.2 - 3.3 nmol / L.

K factor

This factor is calculated by the determination of serum cholesterol and the T4 value.

With this ratio, a single blood sample can be used to diagnose some causes of hypothyroidism.

It is replaced by the T4d test.

  • K value> 1 - standard
  • K-value -4 - +1 - is non-diagnostic and may be the result of primary hypothyroidism or hypothyroidism arising from another disease.
  • A K value of less than -4 indicates primary hypothyroidism.

Thyrotropin: cTSH

Although TSH levels are not as diagnostic as they are in humans, TSH levels are a good indicator of primary thyroid disease compared to secondary (pituitary) thyroid disease.

It is useful in patients suspected of having hypothyroidism or low T4 levels.

Accuracy is improved when the test is performed in conjunction with fT4d.

In primary hypothyroidism, fT4d is low and TSH is high.

In secondary hypothyroidism, fT4d is low and TSH is also low.

Normal: 0.1 - 0.45 ng / ml

A thyroid stimulating hormone response test

It is the most reliable method for diagnosing hypothyroidism in veterinary clinics, but the reagent for the test is very difficult to obtain.

T4 levels are assessed after TSH administration.

In healthy animals, the T4 level doubles and is at least in the lower end of the normal range.

T4 level after TSH stimulation < 1,5 μg/dl jest diagnostyczny dla niedoczynności tarczycy.

Normal in dogs: 1.5-4.5 μg / dl or 19-51 nmol / L, normal in cats: 1-3 μg / dl or 13-39 nmol / L.

Free T4 by dialysis (fT4d)

This test is more accurate than Total T4, TSH, Free T4 (ELISA), or T3 for diagnosing thyroid disease in dogs.

The low level of fT4d has over 90% sensitivity, accuracy and specificity in the diagnosis of hypothyroidism.

Since this test is more expensive and time consuming than other tests, it is best used as a confirmatory test in animals with low T4.

In autoimmune thyroiditis, fT4d levels are low, even when T4 is high.

In disease euthyroidism, fT4d is normal, even when total T4 is low.

Treatment monitoring: TSH

Animals that are adequately treated with l-thyroxine should inhibit pituitary TSH.

Normal TSH levels indicate appropriate therapy.

Correct T4 levels and low TSH indicate proper supplementation.

Thyrotropin Releasing Hormone (TRH) stimulation test

Administration of TRH increases serum T4 levels in healthy cats but does not increase it in cats with hyperthyroidism.

This test is easier to perform than the T3 inhibition test for detecting mild hyperthyroidism in cats.

If the results of this test are inconclusive, thyroid scintigraphy or a T3 suppression test is recommended.

  • T4 level> 50% after TRH administration - normal
  • T4 level < 50% – nadczynność tarczycy.

Antibodies to thyroid hormones

Anti-thyroid antibodies can be produced against thyroglobulin, T3 or T4.

Anti-thyroglobulin antibodies are seen in 50% of dogs with hypothyroidism and are indicative of immune thyroid disease.

Antibodies to T3 or T4 are detected less frequently.

Anti-thyroglobulin antibodies

They occur in u 30-60% dogs with hypothyroidism and are an indicator autoimmune thyroiditis.

T4 / T3 autoantibody test

T4 / T3 antibodies detect hypothyroidism in cases that indicate high T4 levels.

All dogs with anti-T4 and / or T3 antibodies also have anti-thyroglobulin autoantibodies, but not all dogs with anti-T3 antibodies have anti-T4 and / or T3 antibodies.

T4 autoantibodies increase total T4 and fT4 levels and mask hypothyroidism.

Norm: antibodies against T3- < 10 jednostek, przeciwciała przeciw T4 – < 20 jednostek.

T4: Tetraiodothyronine

High serum T4 values ​​indicate an overactive thyroid gland.

It is common in cats and is usually diagnosed with T4 elevations 2-10 fold.

T4 levels, however, are not very helpful in diagnosing hypothyroidism.

Primary thyroid disease (congenital hypoplasia, inflammation, atrophy, or cancer) lowers T4 levels.

Secondary disease resulting from pituitary TSH deficiency and non-thyroid related diseases also lower T4 levels.

Reduced T4 levels should suggest hypothyroidism, but TSH or fT4d testing is necessary to differentiate hypothyroidism from other diseases.

Normal in dogs: 1.5-4.5 pmol / L or 19-51 nmol / L, normal in cats: 1-3 pmol / L or 13-39 nmol / L.

T3 suppression test

It is used to diagnose mild to early hyperthyroidism in cats with high but normal or slightly elevated T4 levels.

T4 levels decline in healthy cats after T3 administration, but remain high in cats with hyperthyroidism.

  • Norm - 50% - lowering the level of T4 or < 1,5 μg/dl.
  • Hyperthyroidism - no decrease in T4 levels after T3 administration.

Hormone tests

Hormone tests

Insulin-like growth factor-1 (IGF-1)

IGF-1, also known as somatomedin C is a polypeptide hormone used in the test for excess growth hormone in dogs.

It is produced predominantly in the liver in response to growth hormone (GH) released from the pituitary gland.

Many of GH's effects are due precisely to its ability to release IGF-1 from the liver, which in turn acts on several different tissues to enhance growth.

IGF levels increase in diabetic cats without increasing growth hormone levels.

Thus, total IGF levels are not a reliable marker of acromegaly in diabetic cats.

Lowering the level is indicative of dwarfism (maintaining body proportions) due to congenital growth hormone deficiency

Level increase - occurs at acromegaly.

Growth hormone stimulation test

Immature dogs and cats with abnormal growth can be growth hormone deficient.

Growth hormone-reactive dermatitis occurs in adult dogs of the following breeds:

  • chow chow,
  • pomeranian,
  • miniature poodle,
  • wolfspitz.

It passes xylazine or clonidine, and then takes a blood sample every 15 minutes for 90 minutes and assesses the level of growth hormone.

Growth hormone levels rise rapidly in 15-30 minutes and return to normal within 90 minutes. A limited response to xylazine indicates a growth hormone deficiency.

Normal GH resting level: 0-10 ng / ml. Post-stimulation GH peak: 25-40 ng / ml within 15-30 minutes. Incorrect result: < 25 ng/ml w ciągu 15-30 minut.


Insulin levels usually correspond to blood glucose levels.

When blood glucose is high, insulin should also be high, and vice versa.

These patterns are important in diagnosing the causes of hypo- and hyperglycemia.

Low glucose levels and high insulin levels (> 26 μU / ml) suggest insulinoma.

High glucose levels and low insulin levels (insulin-dependent diabetes.

High glucose levels and normal or high insulin levels are suggested non-insulin dependent diabetes mellitus.

Normal insulin levels: fasting: < 26 μU/ml, hypoglikemia: < 20 μU/ml, po obciążeniu glukozą: 26-150 μU/ml.

Ratio: insulin / glucose

It indicates whether the insulin response to blood glucose is adequate.

Increased insulin to glucose ratio suggests excess insulin with low blood sugar.

This occurs with an insulinoma or with an overdose of exogenous insulin.

Normal: 0.3, insulin excess:> 0.3, insulin deficiency: < 0,2.


Serum estradiol testing can help detect tumors that are secreting estrogen.

Generally, this test is used for:

  • determining the phase of the sexual cycle (bitch);
  • recognizing disorders of the sexual cycle (bitches);
  • recognizing Sertoli cell tumors (dogs).

In bitches, serum estradiol levels are usually 5-10 pg / ml during sexual rest, 10-20 pg / ml in the proestrus phase (before the onset of heat), 50-100 pg / ml in the late proestrus phase.

However, it does not appear to be a useful test for the reproduction of cats or dogs.


Serum progesterone levels remain below 2 ng / ml up to the ovulation inducing LH peak.

Since ovulation occurs 2 days after an LH spike, elevating progesterone levels can be used to predict optimal mating time.

To predict the fertile period, start progesterone testing every other day after the vaginal smear test shows proestrus (or when serous-bloody vaginal discharge appears).

  • Progesterone levels of 2-5 ng / ml indicate impending ovulation.
  • Levels> 2-5 ng / mL indicate that there is a luteal spike and ovulation should occur within 2 days.
  • Levels of 6-10 ng / ml indicate that ovulation has already occurred and the fertile period is almost complete.
  • Levels> 15 ng / ml occur after the fertile period.
  • Progesterone levels cannot be used to confirm pregnancy in dogs and cats.
  • Progesterone> 10 ng / ml is present in pregnancy, pyomyxia, phantom pregnancy.
  • Progesterone levels> 10 ng / ml occur during pregnancy and fall below this value just before birth.

To predict labor, start a daily progesterone test one week before your expected delivery.

It should occur within 24 hours of lowering progesterone levels < 2 ng/ml.

Relaksin: pregnancy test in bitches

Relaxin is a specific indicator of pregnancy in bitches.

It can be detected in the blood 21 days after embryo implantation and 25 days after ovulation.

It never occurs in the blood of dogs with imaginary pregnancies.


Gastrin is a hormone secreted by G cells in the stomach and duodenum, or through cancer cells in the pancreas.

Serum gastrin normally drops as stomach acidity increases.

Serum gastrin levels are elevated when the stomach contents are alkaline.

High levels of dietary calcium, obstruction of the pylorus of the stomach, dilation of the stomach, liver disease, renal failure, and occasionally pancreatic gastrinomas can increase serum gastrin levels.

High (> 500 pg / ml) or moderately elevated gastrin levels together with acidic gastric pH suggest gastrinoma.

Normal in dogs: 45-125 pg / ml, normal in cats: 28-135 pg / ml.

Gastrin stimulation test

It is used to confirm the diagnosis of a gastrin-secreting tumor in animals with a fasting gastrin level> 500 pg / ml.

After a 24-hour fast, the animal is fed high-protein food, and then its gastrin levels are checked 30 and 90 minutes after the meal.

Normal gastrin levels: after 30 minutes - 200 pg / ml or less, after 90 minutes - 100 pg / ml or less.

Parathyroid hormone (PTH)

PTH acts on the bones and kidneys (classic targets for calcium homeostasis), and on the muscles, heart, immune system, and pancreatic islets.

Maintains normal serum calcium levels by increasing the absorption of calcium from bones, kidneys and intestines and increasing the excretion of phosphorus through the kidneys.

In uremia, PTH causes:

  • muscle dysfunction,
  • cardiomyopathy,
  • dysfunction of leukocytes and T lymphocytes,
  • insulin secretion.

Inhibition of PTH is important in controlling progressive renal failure in uremic patients.

Excess PTH causes hypercalcemia.

Animals with pseudo-malignant secondary hyperparathyroidism have normal or decreased levels of PTH.

The increase in PTH occurs at parathyroid adenoma and kidney failure.

Parathyroid trauma during thyroid surgery is the most common cause of decreased PTH levels with concomitant hypocalcemia.
Normal in dogs and cats: 2-13 pmol / L

Protein-bound parathyroid hormone (PTHrP)

It is secreted by various malignant tumors, but the most common types are lymphoma and adenocarcinoma of the anal glands.

High levels due to hypercalcemia indirectly indicate the malignant nature of the tumor.

Low or undetectable levels of PTHrP during episodes of hypercalcaemia suggest that excess calcium is not associated with malignancy.

Persistent high levels after cancer treatment indicate insufficient tumor control.

Blood tests for gastrointestinal disorders

Blood tests for gastrointestinal disorders

Xylose Absorption Test

Xylose it is a sugar that is absorbed intact from the duodenum.

The xylose absorption test is used to distinguish between mal-digestion and malabsorption.

After 12 hours of fasting, blood is drawn from the patient and then administered orally 5% xylose.

Blood is drawn every 30 minutes for 90 minutes.

Normal dogs' xylose levels reach a high level at 60 minutes, then decline.

Dogs with serum xylose levels above 50 mg / dL at 60 minutes or above 45 mg / dL at 90 minutes are healthy.

Malabsorptive dogs have a flat absorption curve that falls below 50 mg / dL.

Dogs with maldigestion have a normal absorption curve.

Normal xylose level:> 45 mg / dL in 30-90 min, malabsorption: < 44 mg/dl w 30-90 min.

Bentiromide Test (Bt-PABA)

This is a useful test in dogs with maldigestion.

In healthy dogs, pancreatic chymotrypsin acts on bentiromide to obtain free para-aminobenzoic acid (PABA), which is passively absorbed from the gut and its levels measured in the blood.

Normal PABA level 60-90 minutes after bentiromide administration:> 400 μg / dL, abnormal digestion: < 125 μg/dl, nieprawidłowe wchłanianie: 125-400 μg/dl.

Fat absorption test

Fat absorption requires proper bile secretion and pancreatic enzymes for digestion as well as proper lymphatic absorption.

The administration of vegetable oil helps to test the digestibility and absorption of fats.

This test determines the presence of lipemia in a blood sample after administration of vegetable oil.

If lipemia is absent, another portion of the oil enriched with digestive enzymes is administered.

Normally, after administration of the oil, the blood sample should be visible lipemia.

With maldigestion, lipemia is only present after the addition of digestive enzymes.

Even after administration of enzymes, lipemia does not occur with malabsorption.

Vitamin A Absorption Test

The absorption of vitamin A depends on the proper secretion of bile and pancreatic enzymes, as well as on the proper absorption of fat.

This test does not distinguish between maldigestion and malabsorption.

After oral administration of vitamin A, its concentration increases 3-5 times in healthy dogs.

In the case of poor digestion or absorption, the increase in concentration is less than 3 times the basal concentration.

TLI (tripsin-like immunoreactivity)

TLI measures the amount of trypsinogen that is "leaking" from the pancreas.

Normally there is only a trace amount of this inactive enzyme in the blood, even if it is excreted in the urine.

Since this enzyme is not found in other organs, it works like a specific pancreatic marker.

It enters the blood directly from the pancreas and is not lowered in small intestinal disease.

In the case of pancreatic insufficiency, serum TLI levels are lowered.

In acute pancreatitis, it is elevated.

A species specific test should be used.

As trypsinogen is excreted by the kidneys, falsely elevated results may be associated with uremia.

In cats, an increase in TLI is an important signal for acute pancreatitis.

In dogs, it increases earlier and decreases faster than amylase and lipase levels, so all 3 enzymes should be checked.

In cats, TLI levels lower than 8 μg / l, and in dogs, values ​​below 2 μg / l confirm the diagnosis of pancreatic insufficiency.

Normal in dogs: 5-35 μg / l, normal in cats 17-49 μg / l.

Vitamin B12

Absorption of cobalamin only occurs in the ileum.

Since the diets of dogs and cats are usually high in vitamin B12, abnormally low levels are usually associated with chronic malabsorption disorders.

It can be caused by systemic bowel disease that affects the ileum, bacterial overgrowth in the gut, and exocrine pancreatic insufficiency.

To confirm low cobalamin levels associated with bowel disease, folic acid and TLI testing should be performed concurrently.

Cobalamin levels lower than 225 ng / L suggest malabsorption disorders. Valid values ​​depend on the type of test.

Normal in dogs: 225-860 ng / L, normal in cats: 200-1680 ng / L.

Folic acid

Absorption folate it occurs in the proximal part of the small intestine.

Too low levels of folic acid may result from a chronic disease of the proximal parts of the small intestines.

Increased levels occur at bacterial overgrowth in the intestines.

This is often seen in exocrine pancreatic insufficiency but can also arise in intestinal diseases.

Normal in dogs: 7-17 ng / L, normal in cats: 13-38 ng / L.


Parathyroid hormone (PTH), calcitriol and calcitonin control the levels of calcium in the extracellular fluid and bones.

Hypercalcemia can be a sign of a wide variety of diseases.

Serum calcium levels can be increased by:

  • osteolytic bone changes (bacterial osteomyelitis, bone tumors),
  • alleged hyperparathyroidism,
  • hyperparathyroidism,
  • hypervitamosis D,
  • lymphoma,
  • perianal gland tumors,
  • blood thickening,
  • adrenal insufficiency,
  • kidney failure,
  • hyperproteinemia.

Lymphoma is the most common cause of hypercalcemia.

The clinical features of hypocalcaemia depend on the underlying causes, the rate of its development and the presence of acidosis.

The following can lower blood calcium levels:

  • necrotizing pancreatitis,
  • hypoalbuminemia,
  • thyroid surgery,
  • ethylene glycol poisoning,
  • hypoparathyroidism,
  • kidney failure,
  • postpartum tetany.

One of the most common causes of hypocalcaemia is hypoalbuminemia.

Normal in dogs: 9-12 mg / dl or 2.25-3.00 mmol / L, normal in cats: 8-12 mg / dl or 2-3 mmol / L.

Increasing the concentration (hypercalcaemia):

  • dehydration,
  • adrenal insufficiency,
  • advanced renal failure,
  • osteomyelitis,
  • bone tumors,
  • primary hyperparathyroidism (phosphorus levels decrease at the same time),
  • alleged hyperparathyroidism,
  • chronic nephritis with uremia,
  • circulatory failure,
  • emphysema,
  • vitamin D overdose,
  • increased absorption of calcium from the intestines.

Lowering of blood concentration (hypocalcaemia):

  • nephrosis,
  • acute pancreatitis,
  • vitamin D deficiency,
  • kidney failure,
  • glomerulonephritis,
  • hypoparathyroidism,
  • secondary nutritional or renal hyperparathyroidism,
  • atrophic uremia,
  • protein-loving enteropathies,
  • hypoproteinemia,
  • tetanus,
  • pregnancy and lactation,
  • advanced age.

Ionized calcium

Ionized calcium is a physiologically active form of calcium in serum.

In normal animals and during hypercalcemia, ionized calcium usually forms 50-60% total calcium.

In renal failure, ionized values ​​may be lowered by reactions with phosphorus or increased due to acidosis.

In the case of hypocalcaemia without hypoalbuminaemia, ionized calcium is usually low.


Renal failure usually causes normal to low ionized calcium levels with high parathyroid hormone concomitantly.

However, some dogs with severe secondary hyperparathyroidism secondary to renal failure have high ionized calcium.

Primary hyperparathyroidism causes high levels of ionized calcium with high levels of parathyroid hormone.


Clinical manifestations of hypocalcaemia develop when serum total calcium is less than 6.5 mg / dL and ionized calcium is lowered.

Cases with hypoalbuminaemia and low total calcium usually have normal ionized calcium, but ionized calcium is low in some patients with hyipoalbuminaemia.

Acidosis and alkalosis affect ionized calcium levels.

Normal in dogs: 55%, Normal in cats: 60%.


Chlorine is the most important anion in the extracellular space; with the acid-base balance maintained, the serum Cl- content corresponds to the Na concentration+.

Normal in dogs: 350-410 mg / dl or 98.7-115.6 mmol / l, normal in cats: 360-420 mg / dl or 101.5-118.4 mmol / l.

Raising the concentration (hyperchloraemia):

  • dehydration (loss of fluid, decreased fluid intake),
  • tubular acidosis,
  • respiratory alkalosis,
  • high salt diet or therapy,
  • overactive adrenal cortex,
  • diabetes (after insulin therapy),
  • diabetes insipidus,
  • administration of mineralocorticoids (sodium retention),
  • nephropathies,
  • diarrhea from the small intestine.

Lowering concentration (hypochloraemia):

  • loss of chlorine through the kidneys, digestive tract and skin,
  • vomiting,
  • respiratory acidosis,
  • adrenal insufficiency,
  • insufficient intake of NaCl with food,
  • increased water uptake,
  • osmotic diuresis (in diabetes),
  • congestive heart failure (edema),
  • nephropathies,
  • hypoalbuminemia,
  • metabolic alkalosis,
  • after administration of diuretics.

Phosphorus (P ++)

It occurs mainly in the skeletal system and erythrocytes.

Marked in diagnostics:

  • bone diseases,
  • kidney disease,
  • hypoparathyroidism and hyperparathyroidism.

Diet, hormones, and kidney function affect the serum phosphorus level.

Since red blood cells contain a significant amount of phosphorus, hemolysis of the blood sample or delayed separation of the serum from the clot can falsely increase the phosphorus level.

Normal in dogs: 2.2-5.6 mg / dL or 0.94-1.6 mmol / L; age < 1 rok – 5-9 mg/dl, norma u kotów: 2-6,5 mg/dl lub 0,8-1,6 mmol/L; wiek < 1rok – 6-9 mg/dl.

Increasing the concentration (hyperphosphataemia):

  • acute and chronic renal failure,
  • uremia - as the most common cause of hyperphosphatemia,
  • hypoparathyroidism,
  • nutritional background hyperparathyroidism,
  • fresh bone fractures,
  • tumors leading to osteolysis,
  • overactive thyroid gland (in cats),
  • soft tissue injuries,
  • acidosis,
  • obstruction of the urinary tract beyond the kidneys,
  • hypervitaminosis D;,
  • young, growing animals,
  • drugs (furosemide, anabolic steroids),
  • excess phosphorus in the diet.

Lowering concentration (hypophosphataemia):

  • hyperparathyroidism,
  • rickets,
  • osteomalacia,
  • postpartum tetany,
  • diabetes,
  • phosphorus deficiency in the diet,
  • malabsorption syndrome,
  • high lactation,
  • hypovitaminosis D,
  • overactive adrenal cortex,
  • alkalosis,
  • tumors,
  • treatment with glucocorticosteroids, insulin.


Most of the magnesium in the body is found intracellularly, 50% in the bones.

Potassium, magnesium and calcium are closely related.

If the level of one of these positively charged elements is low, another positively charged element is introduced into the intracellular space, causing a reduction in the extracellular blood level.

Serious hypomagnesaemia it interferes with parathyroid hormone secretion causing hypocalcaemia.

Magnesium deficiency occurs as a result of reduced food intake or increased renal loss.

It is a common electrolyte disturbance in critically ill dogs and cats and predisposes them to a variety of cardiovascular, neuromuscular and metabolic problems.

Low levels of magnesium confirm a deficiency in total magnesium in the body, but normal levels do not rule out deficiencies.

Hypermagnesaemia is rare unless the animal is receiving medicines containing magnesium.

Normal in dogs: 1.7-2.9 mg / dl or 0.7 - 1.19 mEq / L, normal in cats: 2.1-3.2 mg / dl or 0.86 -1.31 mEq / NS.

Increasing the concentration (hypermagnesaemia):

  • acute diabetic acidosis,
  • kidney failure,
  • adrenal insufficiency,
  • dehydration,
  • hypocalcemia.

Lowering concentration (hypomagnesaemia):

  • insufficient supply,
  • malabsorption,
  • hypoparathyroidism,
  • hyperaldosteronism,
  • tetany,
  • kidney function disorders,
  • hypercalcemia,
  • hyperkalemia (excess potassium),
  • magnesium deficiency in the body may also be present in normomagnesaemia.


Determined in the differential diagnosis of anemia and deficiency diseases.

Normal in dogs: 94-122 μg / dl or 16.8-21.8 μmol / l, normal in cats: 68-215 μg / dl or 12.2-38.5 μmol / l.

Increasing the iron concentration:

  • hemolytic anemia,
  • viral hepatitis, hepatopathies,
  • nephritis.

Iron Lowering:

  • iron deficiency anemia,
  • chronic blood loss,
  • young animals fed exclusively on milk,
  • cancers,
  • infections,
  • nephrosis.


Potassium is found mainly in intracellular fluid and is excreted by the kidneys under the influence of aldosterone.

Potassium shift into the extracellular space or its excessive loss may cause hypokalemia.

Potassium may be transferred from the plasma to the cells of the body in the course of acute alkalosis, insulin-dependent cellular glucose uptake, or hypothermia.

Vomiting, diarrhea and polyuria also cause loss of potassium.

Renal failure, urethral obstruction, dehydration, and hypoadrenocorticism can cause hyperkalemia severe enough to trigger cardiac arrest.

Potassium levels can be high in serum and intracellular levels low in alkalosis due to the shift.

Normal in dogs: 3.6-5.8 mEq / L or 4.1-5.4 mmol / L or 16-21 mg / dL, normal in cats: 3.7-4.6 mEq / L or 4, 1-5.6 mmol / L or 16-22 mg / dL.

Increasing the concentration (hyperkalaemia):

  • acidosis,
  • kidney failure,
  • dehydration,
  • adrenal insufficiency,
  • oliguria and anuria caused by kidney problems,
  • Burns,
  • acute intestinal obstruction,
  • the presence of urine in the abdomen.

Lowering concentration (hypokalaemia):

  • loss of potassium through the digestive tract (vomiting, diarrhea, intestinal and gastric fistulas),
  • loss of potassium through the kidneys (metabolic acidosis, primary hyperaldosteronism, treatment with adrenal cortex hormones, administration of diuretics),
  • kidney disease,
  • transfer of potassium from the extracellular fluid into the cells (metabolic alkalosis),
  • traumatic shock,
  • intensive fluid therapy,
  • insulin administration,
  • kidney failure.


Sodium levels are high in the extracellular space and in the bones.

Serum sodium levels are controlled by aldosterone, which promotes renal sodium retention.

Low serum sodium levels can be caused by:

  • diarrhea,
  • vomiting,
  • kidney disease,
  • diabetes,
  • adrenal insufficiency,
  • the presence of urine in the abdomen.

Loss of water from the respiratory, urinary or digestive systems occasionally causes dehydration severe enough to increase sodium levels (hypernatremia).

Iatrogenic sodium retention may be triggered by mineralocorticoids, osmotic diuresis, or drugs containing sodium.

A decreased sodium level without significant sodium loss may indicate an aldosterone deficiency.

Increased levels usually indicate dehydration.

Normal in dogs: 140-152 mEq / L or 139.1-156.5 mmol / L or 320-360 mg / dL, normal in cats: 146-155 mEq / L or 143.6-156.5 mmol / L or 330-360 mg / dL.

Increasing the concentration (hypernatraemia):

  • diabetes insipidus,
  • heatstroke,
  • fever,
  • overactive adrenal cortex,
  • hyperaldosteronism,
  • diarrhea,
  • kidney failure.

Lowering concentration (hyponatraemia):

  • chronic glomerulonephritis or chronic renal failure,
  • diarrhea,
  • cirrhosis,
  • hyperlipidemia,
  • excessive sweating,
  • adrenal insufficiency,
  • diabetes,
  • overdose of diuretics,
  • Burns,
  • psychogenic polydipsia.

Serum sodium to potassium ratio

If the Na / K ratio is less than 23, check compounds that dilute the serum (hyperlipidemia, hypertriglyceridemia) or conditions that cause sodium loss (vomiting, diarrhea).

The cause of potassium retention or shift should also be investigated (renal failure, acidosis, shock, abdominal urine).

If neither of these situations is present, hypoadrenocorticism (Addison's disease) is the likely cause and should be confirmed with an ACTH stimulation test (cortisol leveling).

Norm:> 30; probable hypoadrenocorticism: 24-27; adrenal insufficiency: < 23.


Hyponatremia is usually the cause of plasma hypoosmolarity, becoming dangerous at the level < 240 mOsmol/kg.

Hypernatraemia, hyperglycaemia, azotaemia, and ethylene glycol cause hyperosmolarity.

It is dangerous at levels> 350 mOsmol / kg.

Urine osmolarity lower than plasma osmolarity indicates insufficient levels of the antidiuretic hormone (vasopressin)

Norm: plasma osmolarity - dogs: 250-310 mOsmol / kg; cats: 280-310 mOsmol / kg; Urine osmolarity - dogs and cats:> 500 mOsmol / kg.


Measurement of pH enables a preliminary assessment of the type of acid-base disturbance.

Normal in dogs: 7.31-7.42, normal in cats: 7.24 - 7.40.

Bicarbonate (HCO3-, CO2)

Plasma bicarbonate, measured as CO2 or HCO3, is an indicator of acid-base disturbance.

In case of hyperventilation (the occurrence of very fast and deep breaths), decreased bicarbonate levels suggest respiratory alkalosis.

When hyperventilation is absent, decreased levels are usually indicative of metabolic acidosis due to a comorbid condition such as uremia or diabetes mellitus.

An anion gap greater than 20 indicates metabolic acidosis due to organic acid retention.

This is seen in lactic acidosis and ketoacidosis.

An anion gap of less than 20 indicates that acidosis occurs as a result of a loss of bicarbonate (e.g. with kidney disease or diarrhea).

Normal in dogs and cats: 20 mmol / l.

Increasing the alkaline reserve (alkalosis):

  • vomiting,
  • anemia,
  • treatment with salicylates,
  • overdose of therapeutic sodium bicarbonate.

Reduction in the alkaline reserve (acidosis):

  • diarrhea,
  • nephritis,
  • states of hunger,
  • physical effort,
  • emphysema,
  • certain types of pneumonia,
  • some feverish conditions.

Carbon Dioxide (CO2)

Normal in dogs: 16-26 mmol / l, normal in cats: 16-25 mmol / l.

Increasing the concentration:

  • metabolic alkalosis,
  • hypokalemia,
  • respiratory acidosis.

Lowering the concentration:

  • metabolic acidosis,
  • respiratory alkalosis,
  • dehydration.

Serological and special tests

Serological and special tests

Antibodies against acetylcholine receptors

Animals with acquired myasthenia gravis develop antibodies to acetylcholine receptors.

Clinical symptoms include exercise-induced weakness and fatigue, giant esophagus, and dysphagia.

The presence of antibodies indicates immune background myasthenia gravis.

Acute phase proteins

They are glycoproteins not related to immunoglobulins.

They are synthesized in the liver and released into the blood in response to stressors such as inflammation, bacterial infections, endotoxins, cancer, and thermal or mechanical injury.

The biological functions of acute phase proteins vary.

Some act as protease inhibitors, enzymes, transport proteins, clotting factors, and immune response modulators.

However, all proteins appear to play a role in restoring homeostasis following trauma, tissue necrosis, infection or cancer.

Due to changes in the concentration of acute phase proteins (such as. acid alpha glocoprotein) in plasma, they are sensitive and non-specific indicators of inflammation.

AGP is used to detect and monitor infections, inflammatory diseases, and anti-cancer therapy.


Fetal antigens such as alpha fetoprotein are found at low concentrations in healthy animals.

Since cancer cells in the liver produce this fetal protein, it can be used as a malignancy marker.

A high percentage of dogs with hepatocellular adenoma and biliary carcinoma, and some dogs with metastatic liver tumors, produce high levels of AFP.

This marker has a high specificity - in cases where radiographic, ultrasound and other tests suggest primary or metastatic liver tumors, a significantly elevated level of AFP confirms the tumor, but low levels do not rule out malignancy.

Norm: 250 ng / ml.

ANA: Antinuclear Antibody Assay

It detects antibodies to DNA.

Some immune diseases develop autoantibodies against nuclear DNA or the DNA of the cell surface.

Since the ANA test detects these autoantibodies, it is one of the criteria in diagnosing systemic lupus (SLE).

Low antibody titers can also occur in polymyositis in older dogs, rheumatoid arthritis, and allergic drug reactions.

Norm in dogs: < 1:10, norma u kotów: < 1:40.

Lyme disease

Antibodies can be detected in the blood serum using the immunofluorescence test (IFA), ELISA or Western immunoblot techniques.

Titers are difficult to interpret and levels vary from lab to lab.

Cross-reactions with other spirochetes occur in the ELISA and IFA tests.

High antibody titers suggest recent exposure, and rising titers confirm active Borrelia infection.

Catecholamines (adrenaline, noradrenaline, dopamine)

Stress, heart failure, and sympathetic neoplasms can increase serum catecholamines.

Pheochromocytoma of the adrenal gland increases to 2000 pg / ml.

Progressive heart hypertrophy and heart failure also increase norepinephrine levels.

Standard: < 1000 pg/ml.

The most commonly used diagnostic profiles in dogs and cats

The most commonly used diagnostic profiles in dogs and cats

General diagnostic profile

  • Kidneys:
    • urea,
    • creatinine,
    • sodium,
    • potassium,
    • phosphates.
  • Liver:
    • bilirubin,
    • ALT,
    • alkaline phosphatase,
    • GGT,
    • AST,
    • GLDH,
    • total protein,
    • albumin,
    • globulins,
    • albumin to globulin ratio (cat).
  • Pancreas:
    • glucose,
    • alpha amylase,
    • lipase,
    • cholesterol,
    • fructosamine.
  • Muscles:
    • CK,
    • LDH,
    • calcium,
    • magnesium.
  • Metabolism:
    • triglycerides.
  • Hematology:
    • morphology + smear

Geriatric profile

As general diagnostic profile + T4.

Anemia profile

  • morphology + smear,
  • reticulocytes,
  • total bilirubin,
  • LDH,
  • total protein,
  • iron.

Diarrhea profile

  • TLI,
  • Folic acid,
  • vit. B12 (+ parasitological and bacteriological examination of feces).

Electrolyte profile

  • calcium,
  • magnesium,
  • phosphorus,
  • sodium,
  • potassium,
  • chlorides.

Dog epileptic profile

  • albumin,
  • ALT,
  • total bilirubin,
  • glucose,
  • GGT,
  • bile acids,
  • urea;
  • T4 total;
  • cTSH.

Renal profile

  • urea,
  • creatinine,
  • total protein,
  • glucose,
  • sodium,
  • potassium,
  • calcium,
  • phosphorus,
  • SDMA.

Claw profile

  • Anaplasma phagocytophilum,
  • Anaplasma platys,
  • Babesia spp.,
  • Borrelia spp.,
  • Ehrlichia canis,
  • Hepatozoon canis,
  • Dirofilaria immitis.

Diagnostics of pu / pd (polyuria and increased thirst)

  • creatinine,
  • calcium,
  • sodium,
  • potassium,
  • glucose,
  • fructosamine,
  • ALT,
  • alkaline phosphatase,
  • bile acids,
  • total protein,
  • albumin,
  • morphological examination with a smear,
  • urine test + UPC,
  • cortisol to creatinine ratio,
  • fT4.

Vomiting - diagnosis

  • bile acids,
  • urea,
  • creatinine,
  • sodium,
  • potassium,
  • calcium,
  • glucose,
  • alkaline phosphatase,
  • ALT,
  • total protein,
  • albumin,
  • cPl,
  • morphology.

Pancreatic-intestinal profile

  • TLI,
  • Folic acid,
  • vitamin B12.

Pancreatic profile

  • ALT,
  • alpha amylase,
  • AST,
  • cholesterol,
  • glucose,
  • lipase,
  • potassium,
  • sodium
  • calcium;
  • morphology.

Hepatic profile

  • albumin,
  • ALT,
  • AST,
  • AP,
  • total protein,
  • direct bilirubin,
  • total bilirubin,
  • GLDH,
  • GGT,
  • urea.

Preoperative profile

  • ALT,
  • AP,
  • total bilirubin,
  • creatinine,
  • urea,
  • morphology,
  • PT,
  • APTT.

BARF profile

  • zinc,
  • phosphorus,
  • iodine,
  • copper,
  • calcium,
  • T4 total,
  • Vitamin A,
  • vitamin D
  • determination of the blood group.

Cat profile

Like general diagnostic profile plus:

  • detection of FeLV antigen,
  • detection of antibodies against FIV,
  • anti-coronavirus antibody titer,
  • serum protein electrophoresis.

Profile of the upper respiratory tract

  • Chlamydophila felis,
  • Mycoplasma felis,
  • FHV 1 (herpesvirus),
  • Calicivirus (FCV).

Hemotropic mycoplasma profile

  • Mycoplasma haemofelis,
  • Cand. Mycoplasma haemominuhim,
  • Cand. Mycoplasma turicensis.

Ophthalmic profile

  • Chlamydophila felis,
  • Mycoplasma felis,
  • FHV1.

FIP profile

  • AST,
  • total protein,
  • bilirubin,
  • morphology,
  • FCoV - antibodies,
  • protein electrophoresis.

Epilepsy profile

  • albumin,
  • ALT,
  • total bilirubin,
  • glucose,
  • fructosamine,
  • bile acids,
  • urea,
  • T4 total.


Test results should not be compared with those of another dog or cat.

Each animal is different, and the values ​​of some parameters can fundamentally change even during the day.

Instead, it is good to monitor the values ​​against previous studies.

Animal blood control tests should be performed once a year, and certainly not less frequently than once in two years.

What it looks like blood sampling in a dog and a cat you can see in the video below

Veterinary Technician Training: Lab Skills 1: Part 1 - Basic Blood Collection
Watch this video on YouTube

In the case of dog or cat breeds predisposed to certain medical conditions, it is worth increasing the frequency of testing.

Also, animals that have been ill before should be monitored more frequently.

In dogs or cats with active diseases, the frequency and extent of check-up is usually recommended by the attending veterinarian.

Sources used >>

Leave Your Comment