Blood test in cats: interpretation, norm and deviations

Owners, when bringing a sick cat to a veterinary clinic, are almost constantly faced with the fact that veterinary specialists, in addition to a clinical examination of the sick cat, examine blood samples from the sick animal in order to make an accurate diagnosis of the disease. Modern effective treatment of a sick animal cannot be based only on examining the sick animal.

If not so long ago no one seriously took the possibility of conducting a study to assess the condition of an animal using a clinical and biochemical blood test in the laboratory, today every self-respecting veterinary specialist, and even more so a modern veterinary clinic, considers it the norm to do a blood test on their patients.

A blood test is one of the most informative ways to examine pets. By conducting a blood test, a veterinarian has the opportunity not only to confirm or refute the clinical diagnosis, but also to identify hidden pathological processes in the animal’s body (subclinical pathology) that have not yet produced characteristic symptoms.

The main types of research are general clinical and biochemical blood tests. Using the CBC, you can establish the basic composition of the blood. Biochemical research allows a veterinary specialist to more accurately judge the functional state of the animal. Before performing an operation or other intervention, a blood test is a mandatory norm.

How to properly prepare an animal for blood donation

Before taking blood for analysis, the cat is not fed for 10-12 hours, and there must be free access to water.
We limit the animal’s physical activity (refusal of games, etc.).
Taking any medications is prohibited. If your cat regularly takes any medications as prescribed by your veterinarian, consult about stopping them.
Before taking blood, therapeutic procedures, ultrasound, x-rays, and massage are unacceptable.

The procedure for taking blood for analysis

Blood is taken from the vein of the animal. To do this, the cat is placed on its side, and if the cat resists, it is secured in a special veterinary bag. Blood is taken from the front paw by shaving off a small area of fur. The injection site is treated with a disinfectant solution, a needle from a disposable syringe is inserted into the vein, blood in the amount of 2 ml is drawn into a test tube with heparin or sodium citrate.

What blood tests are performed in veterinary clinics?

In modern veterinary clinics, two laboratory blood tests are performed:

General or clinical.
Biochemical.

General blood test for a cat

A general blood test based on the number and condition of formed blood elements shows the health status of the cat’s body. When performing a general blood test, parasites such as dirofilaria (dirofilariasis), hemobartenella can be detected in a cat’s blood.

What indicators does the clinic’s veterinary specialist receive when conducting a general blood test:

Hematocrit
Hemoglobin.
Average content and concentration of hemoglobin in an erythrocyte.
Color indicator.
ESR (erythrocyte sedimentation rate).
Red blood cells.
Leukocytes.
Neutrophils.
Lymphocytes.
Eosinophils.
Monocytes.
Platelets.
Basophils.
Myelocytes.

Biochemical blood test for a cat

Biochemical blood tests allow veterinary specialists to identify subclinical (hidden) cat diseases. A biochemical blood test allows you to determine the functioning of the body’s enzymatic system and provide information about damage to a particular organ in a cat.

A biochemical blood test for a cat includes enzymatic, electrolyte, fat and substrate indicators.

Basic biochemical parameters:

Glucose.
Protein and albumin.
Cholesterol.
Bilirubin is direct and total.
Alanine aminotransferase (ALT).
Aspartate aminotransferase (AST).
Lactate dehydrogenase.
Gamma glutamyl transferase.
Alkaline phosphatase.
a –Amylase.
Urea.
Creatinine.
Calcium.
Magnesium.
Creatine phosphokinase.
Triglycerides.
Phosphorus, inorganic.
Electrolytes (potassium, calcium, sodium, iron, chlorine, phosphorus).

Why is regular testing necessary?

For some reason, people ignore blood tests for both themselves and their pets. Today we will talk about the second case.

Any veterinarian or entire veterinary clinic cannot begin to diagnose the problem without having recent blood tests on the animal. Every day, owners lose precious minutes of time that could be spent helping their pet.

Having a blood test in front of him, the veterinarian is able to immediately confirm the presence of a particular disease, or begin treatment of your friend’s maturing sore.

Indicators of blood tests obtained and their characteristics

Each indicator of a blood test shows the functioning of individual organs or entire systems, while the veterinarian takes into account not only each data separately, but also the relationship to each other.

Hematocrit is a conditional indicator showing the ratio of all formed elements of blood to its volume, i.e. determines the thickness of blood. Shows how much blood can carry oxygen.

Hemoglobin is a protein contained in red blood cells that ensures the movement of oxygen and carbon dioxide throughout the animal’s body.

The average concentration of hemoglobin in an erythrocyte shows in percentage terms how much erythrocytes are saturated with hemoglobin.

The color (color) blood index shows how much hemoglobin is contained in red blood cells in relation to the normal value.

ESR is an indicator that determines the presence of an inflammatory process in the body.

Erythrocytes are red blood cells that take part in tissue gas exchange and maintaining acid-base balance. It’s bad when test results go beyond the norm, not only in the direction of decrease, but also of increase.

Leukocytes (white blood cells) - indicate the state of the animal’s immune system. Leukocytes include lymphocytes, neutrophils, monocytes, basophils and eosinophils. For a veterinarian, the relationship between these cells is of diagnostic importance.

Neutrophils are responsible for destroying bacteria in the blood.
lymphocytes - speak of a general indicator of immunity.
monocytes - perform the function of destroying foreign substances in the blood,
caught in the blood.
eosinophils - perform the function of fighting allergens.
basophils - together with other leukocytes, help the body recognize and identify foreign particles that have entered the blood.

Platelets are blood cells responsible for blood clotting. In addition to this function, they are responsible for the integrity of blood vessels. Both high and low levels of them are dangerous for the body.

Myelocytes are located in the bone marrow and normally should not be in the blood.

Leukocyte formula

This percentage of different types of white blood cells is determined by counting a stained blood smear under a microscope.

Neutrophils

A type of white blood cell responsible for creating a response to inflammation, destroying bacterial infections in the blood, dead and damaged cells. Form nonspecific immunity. The age of a neutrophil is estimated by the shape of the nucleus. An increase in the proportion of young cells may indicate the severity of the inflammatory reaction.

Norm: 60-75% for mature neutrophils (segmented) and up to 6% of young (band) neutrophils.

Lymphocytes

They are the main cells of the immune system. They form specific immunity by producing antibodies.

Norm: from 18 to 25%.

Eosinophils

They form antiparasitic immunity and participate in allergic reactions.

Norm: from 1 to 5%.

Basophils

Together with other leukocytes, they recognize foreign particles in the blood. Their presence in the blood may indicate an immediate acute allergic reaction (anaphylactic shock).

Norm: from 0 to 1%.

Blood chemistry

Glucose is an informative indicator indicating the functioning of a complex enzymatic system in the body, including individual organs (liver, pancreas, kidneys). Glucose metabolism in the body involves 8 different hormones and 4 complex enzymatic processes. A disorder is considered to be either high or low blood sugar levels in a cat.

Total protein in the blood reflects the correctness of amino acid metabolism in the body. Shows the total amount of all protein fractions - globulins and albumins. Proteins in an animal’s body take part in almost all life processes of the body. For specialists, both their increased and decreased amounts are important.

Albumin is the most basic blood protein produced by the liver. Albumin in a cat’s body performs a large number of functions (transporting nutrients, maintaining reserve reserves of amino acids for the body, maintaining osmotic blood pressure, etc.).

Cholesterol is a structural component that ensures the strength of cellular structures and takes part in the synthesis of many vital hormones. Veterinary experts judge lipid metabolism in a cat’s body based on cholesterol levels.

Bilirubin is a bile pigment found in the body in two forms - direct and indirect. Indirect bilirubin is formed in the blood as a result of the breakdown of red blood cells, and bound (direct) bilirubin is converted from indirect bilirubin in the liver. Bilirubin shows the functioning of the hepabiliary system (biliary and hepatic). Refers to “color” indicators i.e. when its content in the body is increased, the tissues turn yellow (jaundice).

Alanine aminotransferase (ALT, ALaT) and aspartate aminotransferase (AST, ACaT) are enzymes produced by liver cells, heart cells, red blood cells and skeletal muscles. It is an indicator of the functions of these organs or departments.

Lactate dehydrogenase (LDH) is an enzyme involved in the final step in the breakdown of glucose. Veterinary LDH specialists monitor the functioning of the cardiac and hepatic systems, and also judge the risks of tumor formation.

ɤ-glutamyltransferase (Gamma-GT) – in combination with other liver enzymes, provides insight into the functioning of the hepabilary system, pancreas and thyroid glands.

Alkaline phosphatase is determined to monitor liver function.

ɑ-Amylase – produced by the pancreas and parotid salivary gland. Their work is judged by its level, but always in conjunction with other indicators.

Urea is the result of protein processing, which is excreted by the kidneys. Some remains circulating in the blood. Using this indicator, you can check your kidney function.

Creatinine is a muscle byproduct excreted from the body by the renal system. The level fluctuates depending on the condition of the urinary excretory system.

Potassium, calcium, phosphorus and magnesium are always assessed in complex and in relation to each other.

Calcium is involved in the conduction of nerve impulses, especially through the heart muscle. By its level, you can determine problems in the functioning of the heart, muscle contractility and blood clotting.

Creatine phosphokinase is an enzyme that is found in large quantities in the skeletal muscle group. By its presence in the blood, one can judge the work of the heart muscle, as well as internal muscle injuries.

Triglycerides in the blood characterize the functioning of the cardiovascular system, as well as energy metabolism. Usually analyzed in conjunction with cholesterol levels.

Electrolytes are responsible for membrane electrical properties. Thanks to the electrical potential difference, cells pick up and execute commands from the brain. In pathologies, cells are literally “thrown out” from the nerve impulse conduction system.

What problems are most common?

What deviations from the norm occur most often? In cats, as in dogs, especially if the owner does not feed his pet properly, high or low cholesterol levels occur. What does each option mean?

If cholesterol exceeds the norm, this may indicate problems with the liver and lack of thyroid function. Low cholesterol may indicate a malignant neoplasm (in rare cases) or hepatopathy, that is, a certain list of liver diseases.

Pet owners also often encounter problems with glucose. Elevated glucose levels may mean your pet has pancreas or liver problems. Low glucose indicates possible starvation of the animal, an overdose of insulin or severe poisoning.

It is important to understand that these are just examples of what can happen. In other cases, there may be more rare diseases. We have mentioned the diseases that occur most often.

Norms of blood tests in cats

General (clinical) blood test
Blood chemistry

The name of indicators	Units	Norm
Ø hematocrit	% (l/l)	26-48 (0,26-0,48)
Ø hemoglobin	g/l	80-150
Ø average hemoglobin concentration in an erythrocyte	%	31-36
Ø average amount of hemoglobin in a red blood cell	pg	14-19
Ø color indicator;	0,65-0,9
Ø ESR	mm/hour	0-13
Ø red blood cells	million/µl	5-10
Ø leukocytes	thousand/µl	5,5-18,5
Ø segmented neutrophils	%	35-75
Ø band neutrophils	%	0-3
Ø lymphocytes	%	25-55
Ø monocytes	%	1-4
Ø eosinophils	%	0-4
Ø platelets	million/l	300-630
Ø basophils	%	—
Ø myelocytes	%	—

Norms of blood tests in cats

General (clinical) blood test

Blood chemistry

The name of indicators	Units	Norm
Ø glucose	mmol/l	3,2-6,4
Ø protein	g/l	54-77
Ø albumin	g/l	23-37
Ø cholesterol	mmol/l	1,3-3,7
Ø direct bilirubin	µmol/l	0-5,5
Ø total bilirubin	µmol/l	3-12
Ø alanine aminotransferase (ALT)	U/l	17 (19) -79
Ø aspartate aminotransferase (AST)	U/l	9-29
Ø lactate dehydrogenase	U/l	55-155
Ø ɤ-glutamyltransferase	U/l	5-50
Ø alkaline phosphatase	U/l	39-55
Ø ɑ-Amylase	U/l	780-1720
Ø urea	mmol/l	2-8
Ø creatinine	mmol/l	70-165
Ø calcium	mmol/l	2-2,7
Ø magnesium	mmol/l	0,72-1,2
Ø creatine phosphokinase	U/l	150-798
Ø triglycerides	mmol/l	0,38-1,1
Ø inorganic phosphorus	mmol/l	0,7-1,8
Ø Electrolytes
Ø potassium (K+)	mmol/l	3,8-5,4
Ø calcium	mmol/l	2-2,7
Ø sodium (Na+)	mmol/l	143-165
Ø iron	mmol/l	20-30
Ø chlorine	mmol/l	107-123
Ø phosphorus	mmol/l	1,1-2,3

Blood tests in cats (transcript)

All deviations in indicators are considered in complex and in relation to one data to another within the same results from the study of one blood sample. Only an experienced veterinarian should interpret blood tests (results).

General (clinical) blood test

The name of indicators	Promotion	Decline
1. Hematocrit	erythremia (distortion of the process of blood formation with a sharp increase in red blood cells in the blood); heart failure; pulmonary failure; dehydration; debilitating vomiting, diarrhea; burns.	anemia; chronic inflammation; prolonged hunger; oncology; after various multiple intravenous infusions; renal failure.
2. Hemoglobin	dehydration; hemoblastoses; stress; hemolysis of red blood cells; hypoxia.	anemia; profuse blood loss.
3. ESR	pregnancy; anemia; malignant oncology; inflammation and infections; intoxication of the body; leukemia; kidney problems; after surgical interventions.	dehydration; cardiovascular diseases; jaundice (with a simultaneous increase in bile acids); with an increase in albumin levels; liver damage; drop in fibrinogen levels.
4. Red blood cells	erythremia; lung or heart disease; excessive physical activity; FOS poisoning; dehydration; heart defects.	chronic inflammation; heavy blood loss; increased amount of fluid introduced into the body.
5. Leukocytes	purulent-inflammatory processes; viral or bacterial infections; allergic reactions; poisoning; tumors; helminthic infestations; lympho- or myeloid leukemia; heart attack	liver diseases; after active antibiotic therapy; poisoning; radiation sickness; autoimmune diseases of cats; aplastic anemia; panleukopenia (feline distemper); chronic inflammation, sepsis; diseases of the central nervous system.
6. Segmented neutrophils (mature)	inflammation; hemolytic anemia; states of shock; intoxication; myocardial infarction.	toxoplasmosis; aplastic anemia; fungal infections; chronic bacterial lesions.
7. Band neutrophils (immature)	malignant tumors; sepsis; myeloid leukemia; heavy bleeding; acute inflammation; shock or coma; intoxication; excessive physical activity; acidosis.
8. Lymphocytes	infections; stress; binge eating; after physical exercise; anemia; lymphocytic leukemia; adrenal hypofunction; hypofunction of the ovaries.	malignant lymphomas; radiation sickness; immunosuppression; long-term corticosteroid therapy; autoimmune diseases.
9. Monocytes	malignant tumors; chronic infections; monocytic leukemia; blood parasitic diseases.	severe infections; sepsis.
10. Eosinophils	allergies; tumors; helminthic infestations; hemoblastoses.
11. Platelets	internal inflammation; thrombosis of large veins.	chronic leukemia; aplastic anemia; autoimmune hemolytic anemia; cirrhosis of the liver; autoimmune diseases; intoxication; - incoagulability of blood.
12. Basophils	hemoblastoses	Normally absent
13. Myelocytes	chronic myeloid leukemia; sepsis; bleeding; chronic or acute inflammation.	Normally none.

Blood chemistry

The name of indicators	Promotion	Decline
1. Glucose	stress; diabetes; pathology of the pancreas; hyperfunction of the thyroid gland.	insulinoma; insulin overdose; fasting for a long time; disturbances in the functioning of the endocrine system; severe intoxication with damage to liver function.
2. Protein	dehydration; chronic inflammatory processes; autoimmune diseases; multiple myeloma; extensive burns.	prolonged fasting; renal pathologies; violation of intestinal absorption function; hepatitis; cirrhosis; extensive blood loss; presence of parasites.
3. Albumin	There is no true drop in albumin levels, most often due to dehydration and a decrease in total protein.	Likewise with the decrease in total protein.
4. Cholesterol	hypothyroidism; pancreatitis; kidney disease; diabetes.	poor nutrition; malignant tumors; insufficient absorption in the intestine.
5. Direct bilirubin	liver pathologies; obstruction of the bile ducts and bile stagnation; leptospirosis.
6. Total bilirubin	hypovitaminosis B12; hemolysis (decomposition of red blood cells).	bone marrow diseases; anemia; tissue fibrosis (fibrin deposition).
7. Alanine amino-transferase (ALT, ALaT)	destruction of liver cells due to tumors, cirrhosis, jaundice; muscle damage or injury; burns; liver intoxication.
8. Aspartate aminotransferase (AST, ASat)	excessive physical activity; liver pathologies (hepatitis, malignant oncology); burns; heart failure; heatstroke.	infectious hepatitis (with a simultaneous increase in ALT).
9. Lactate dehydrogenase	5-7 days after myocardial infarction; infectious peritonitis of cats; necrosis; leukemia; pancreatitis; nephritis; tumors; skeletal muscle injuries; hemolytic anemia.
10. ɤ-glutamyl transferase	cirrhosis of the liver; violation of the outflow of bile and its stagnation; disorders of the pancreas; hepatitis.
11. Alkaline phosphatase	bone tumors; softening of bone tissue (osteomalacia) during the healing period of fractures; narrowing of the bile ducts and neoplasms of the gallbladder; bacterial lesions of the stomach and intestines; pregnancy; abuse of fatty foods; various liver pathologies.	extended therapy with corticosteroids; hypothyroidism; anemia; hypovitaminosis C.
12. ɑ-Amylase	renal failure; peritonitis; pancreatitis; general intoxication; inflammation of the parotid salivary glands; diabetes; volvulus of the intestines or stomach.	necrotic processes in the pancreas; thyrotoxicosis; poisoning (barbiturates or arsenic); use of anticoagulants.
13. Urea	excess protein in feed; kidney diseases; hemolytic anemia; states of shock; stress overexertion; myocardial infarction; prolonged vomiting or diarrhea.	severe liver pathologies; lack of protein intake from food.
14. Creatinine	renal dysfunction; osteodystrophy; blockage of the urinary ducts; dehydration; usually increases with urea.	pregnancy; reduction in muscle size due to age-related changes.
15. Calcium	excessive work of the parathyroid glands; leukemia; oncology; diseases of the skeletal system; chronic renal failure; excess vitamin D.	anticonvulsant therapy; softening of bones; pancreatitis; hypovitaminosis D; lack of functioning of the parathyroid glands; cirrhosis of the liver.
16. Magnesium	renal failure; dehydration; long-term therapy with progesterone, magnesium preparations; injuries.	pregnancy; prolonged diarrhea, vomiting; use of diuretics; general lack of magnesium in the body; pancreatitis.
17. Creatine phosphokinase	myocardial infarction; postoperative period; injuries; infections; convulsions; intoxication with sedatives; excessive physical activity.
18. Triglycerides	pancreatitis; diabetes; hepatitis; myocardial infarction; cardiac ischemia; renal dysfunction; pregnancy; cirrhosis; stress; jaundice.	hunger; infections; obstructive pulmonary disease; use of heparin and ascorbic acid.
19. Inorganic phosphorus	bone destruction due to bone tumors and leukemia; excess vitamin D, endocrine abnormalities; problems with the kidneys.	malabsorption in the intestine; lack of vitamin D, excess calcium; lack of growth hormone; prolonged diarrhea and vomiting.
20. Electrolytes
· potassium	pathologies of the thyroid gland; renal failure; prolonged fasting; lack of vitamin D, tumors; periostitis.	chronic hunger; long-term treatment with cortisone or adrenal hyperfunction; diarrhea and vomiting; deficiencies in kidney function.
· sodium	excess salt in food; frequent urination with diabetes insipidus; disruptions in water-salt metabolism (coma, hypothalamic pathologies); kidney pathologies.	renal pathologies; abuse or overdose of diuretics; swelling; frequent urination with diabetes; heart failure.
· iron	various kidney inflammations; liver pathologies in the form of cirrhosis, hepatitis, fatty degeneration; improper or long-term use of estrogen; intoxication with lead products.	anemia; any postoperative period; infectious processes; cancer; nephrotic syndrome.
· chlorine	diabetes; overdose of corticosteroids; renal failure; disruption of the adrenal glands; traumatic brain injuries.	increased sweating; jades; long-term therapy with diuretics; diarrhea, vomiting; respiratory acidosis (accumulation of carbon dioxide in the blood).
· phosphorus	hypothyroidism; kidney failure; diabetes.	disruptions in the gastrointestinal tract; intravenous administration of large amounts of glucose against the background of active insulin therapy; rickets; lack of vitamin D; severe, recurring diarrhea.

What tests are performed in veterinary clinics?

To ensure that your pet is always healthy and there is no threat of disease, it is recommended to carry out analysis regularly once a year. If the cat has been ill, then after six months it is recommended to donate blood again.

There are three different approaches to identifying diseases using analysis.

An integrated approach involves studying the maximum amount of data. Prescribed only when previous studies have not made it possible to make an accurate diagnosis.
The partial approach is used to exclude diseases with similar symptoms.
Single is used to check the established diagnosis.

Regular visits to the veterinary clinic will save your pet from many diseases.
When diagnosing, the following types of blood tests can be used:

general. Determines the overall picture of the pet’s health. Helps identify inflammatory processes, allergies and other diseases;

biochemical analysis. Helps establish a diagnosis with inaccurate symptoms. Allows you to determine exactly where the problem is and how affected the internal organs are;

hormonal analysis. There are a large number of endocrine (hormonal) diseases in animals, so analysis of the level of hormones in the blood is an integral step in the diagnosis of these diseases.

But the main ones are general and biochemical analysis.