Creatinine is elevated in a cat. Stages of CKD according to creatinine in cats

Update: October 2017

A blood test is one of the most informative ways to examine any animal. With the help of it, one can not only confirm or refute clinical diagnoses, but also reveal hidden pathological processes that have not yet given characteristic symptoms.

Types of blood tests, test material

There are two main laboratory blood tests:

• general (or clinical);
• biochemical.

cat

Main characteristics:

• hemoglobin;
• hematocrit;
• the average content and concentration of hemoglobin in the erythrocyte;
• color indicator;
• ESR (erythrocyte sedimentation rate);
• leukocytes;
• erythrocytes;
• neutrophils;
• lymphocytes;
• eosinophils;
• monocytes;
• platelets;
• basophils;
• myelocytes.

Material for analysis:

Venous blood, at least 2 ml, placed in a test tube with a special anticoagulant medium (heparin or sodium citrate), which prevents its coagulation and destruction of blood shaped elements(blood cells).

Blood chemistry

Hidden pathologies in the cat's body are revealed. The study provides information about the lesion of a particular organ or a specific organ system, as well as an objective assessment of the degree of this lesion. The result is determined by the work of the enzymatic system, reflected in the state of the blood. A biochemical blood test in a cat includes enzyme, electrolyte, fat and substrate indicators.

Main characteristics:

• glucose;
• protein and albumin;
• cholesterol;
• bilirubin direct and total;
• alanine aminotransferase (ALT)
• aspartate aminotransferase (AST);
• lactate dehydrogenase;
• gamma-glutamyltransferase;
• alkaline phosphatase;
• ɑ-amylase;
• urea;
• creatinine;
• calcium;
• magnesium;
• creatine phosphokinase;
• triglycerides;
• phosphorus inorganic;
• electrolytes (potassium, calcium, sodium, iron, chlorine, phosphorus).

Material for analysis:

Serum with a volume of about 1 ml ( deoxygenated blood taken on an empty stomach and placed in a special test tube, which allows you to separate the blood serum from its formed elements).

Venous blood is taken from the anterior or back paw by a veterinarian using local anesthetic sprays. Usually does not deliver discomfort pet if the doctor has certain skills.

Before the planned blood sampling, it is necessary to exclude:

• excessive physical activity cats;
• the introduction on the eve of any medications;
• any physiotherapy measures, ultrasound, x-rays and massages before the procedure itself;
• food intake 8-12 hours before biochemical analysis.

The main indicators of blood tests and their characteristics

Each indicator is responsible for one or another degree of health / ill health in the cat's body, and also shows the work of individual organs or entire systems. It is not only each data separately that matters, but also in relation to each other.

General (clinical) blood test

• Hematocrit- a conditional indicator showing the ratio of all blood cells to its total volume. Another name is hematocrit and often the ratio of not all blood cells is determined, but only red blood cells. In other words, it is the density of blood. Shows how much blood is able to carry oxygen.
• Hemoglobin- the content of red blood cells responsible for transporting oxygen throughout the body and removing waste carbon dioxide. Deviation from the norm is always a sign of a particular pathology in the circulatory system.
• The average concentration of hemoglobin in the erythrocyte shows in percentage terms how erythrocytes are saturated with hemoglobin.
• The average content of hemoglobin in an erythrocyte has approximately the same value as the previous indicator, only the result is noted by a specific amount of it in each erythrocyte, and not by a general percentage.
• Color (color) indicator blood shows how much hemoglobin is contained in erythrocytes, in relation to the normal value.
• ESR- an indicator by which traces of the inflammatory process are determined. The erythrocyte sedimentation rate does not indicate a specific disease, but indicates the presence of disorders. In which particular organ or system can be determined in conjunction with other indicators.
• red blood cells- red blood cells involved in tissue gas exchange, retention acid-base balance. It is bad when the test results go beyond the norm, not only in the direction of decrease, but also growth.
• Leukocytes- or white blood cells, which show the state of the animal's immune system. Includes lymphocytes, neutrophils, monocytes, basophils, basophils and eosinophils. Diagnostic value has the ratio of all these cells to each other:
  • neutrophils- responsible for destruction bacterial infection in blood;
  • lymphocytes – total score immunity;
  • monocytes– are engaged in the destruction of foreign substances that have entered the bloodstream and threaten health;
  • eosinophils- stand guard in the fight against allergens;
  • basophils- "work" in tandem with other white blood cells, helping to recognize and identify foreign particles in the blood.

• platelets- blood cells responsible for its coagulation. They are also responsible for the integrity of the vessels. Both the growth of this indicator and its decline are important.
• Myelocytes are considered a type of leukocytes, however, they are a somewhat isolated indicator, tk. are in the bone marrow and normally should not be detected in the blood.

Blood chemistry

• Glucose is considered a very informative indicator, because indicates the work of a complex enzymatic system in the body, including individual bodies. The glucose cycle involves 8 different hormones and 4 complex enzymatic processes. Pathology is considered as an increase in the level of sugar in the blood of a cat, and its fall.
• total protein in the blood reflects the correctness of amino acid (protein) metabolism in the body. Shows the total amount of all protein components - globulins and albumins. All proteins take part in almost all vital processes of the body, so both their quantitative growth and decrease are important.
• Albumen is the most important blood protein produced by the liver. Performs a lot of vitality important functions in the body of a cat, therefore it is always determined separately from total protein indicator (transfer of useful substances, preservation of reserve stocks of amino acids for the body, preservation osmotic pressure blood, etc.).
• Cholesterol is one of the structural cellular components, providing their strength, and is also involved in the synthesis of many vital hormones. It can also be used to judge the nature of lipid metabolism in the body of a cat.
• Bilirubin- bile component, consisting of two forms - indirect and direct. Indirect is formed from erythrocyte decay, and bound (direct) is converted in the liver from indirect. Directly shows the work of the hepabiliary system (biliary and hepatic). Refers to "color" indicators, because. when it is exceeded in the body, tissues are stained in yellow(sign of jaundice).
• Alanine aminotransferase (ALT, ALaT) and aspartate aminotransferase (AST, ASaT)- enzymes produced by liver cells, skeletal muscles, heart cells and red blood cells. It is a direct indicator of the functions of these organs or departments.
• Lactate dehydrogenase (LDH)- an enzyme that is involved in the final step in the breakdown of glucose. Determined to control the functioning of the hepatic and cardiac systems, as well as at the risk of tumor formation.
• ɤ-glutamyltransferase (Gamma-GT)- in combination with other liver enzymes gives an idea about the work of the hepabiliary system, pancreas and thyroid glands.
• Alkaline phosphatase determined to control liver function.
• ɑ-amylase- Produced by the pancreas and parotid salivary gland. By its level, their work is judged, but always in conjunction with other indicators.
• Urea- the result of the processing of protein, which is excreted by the kidneys. Some remain circulating in the blood. By this indicator, you can check the work of the kidneys.
• Creatinine- a by-product of muscle excreted from the body by the renal system. The level fluctuates depending on the state of the excretory urinary system.
• Potassium, calcium, phosphorus and magnesium are always evaluated in a complex and in relation to each other.
• Calcium is a participant in nerve impulses especially through the heart muscle. According to its level, problems in the work of the heart, contractile properties of muscles and blood clotting can be determined.
• Creatine phosphokinase is an enzyme that huge number found 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 work of cardio-vascular system and energy exchange. It is usually analyzed in combination with cholesterol levels.
• electrolytes are responsible for membrane electrical properties. Thanks to the electrical potential difference, the cells pick up and execute the commands of the brain. In pathologies, cells are literally "ejected" from the conduction system of nerve impulses.

Norms of blood tests in cats

General (clinical) blood test

Blood chemistry

Blood tests in cats (decoding)

All deviations in indicators are considered in a complex and by the ratio of some data to others within the same results for the study of one blood sample. Only a specialist should deal with the interpretation of blood tests (results).

Blood incoagulability.

• chronic myeloid leukemia;
• sepsis;
• bleeding;
• chronic or acute inflammation.

Both clinical and biochemical blood tests are important clinical significance for correct setting diagnosis and detection of hidden internal pathologies.

Creatinine is the end product of the creatinine phosphate reaction. This substance is formed in the muscles, and then released into the blood. By determining its level in the blood of a pet, you can diagnose several of its pathological conditions. Elevated creatinine in a cat indicates, first of all, a violation of the work excretory system.

This substance is formed in the body of an animal from the protein creatine, which is a source of energy and nutrition for skeletal muscles. Normal blood levels can fluctuate depending on the cat's weight and speed. metabolic processes occurring in his body. In young and mobile animals, this figure is usually higher than in old ones.

The norm of creatinine in the blood of domestic cats is 40-130 µmol/liter. This indicator, among other things, can depend on the sex of the animal and the development of its muscle mass.

When does the level rise?

Most often, the presence is too a large number this substance in the blood of an animal indicates renal failure or nephropathy. The creatinine-phosphate reaction occurs when the cat's muscles contract. In this case, the connection is divided into three components:

• water;
• creatinine;
• phosphorus.

All three components are subsequently excreted from the body of the animal with urine. If the kidneys are not working well, creatinine is retained in the cat's body. Gradually, it begins to accumulate in the blood of the animal.

However, it is impossible to diagnose renal failure only on such a basis as elevated creatinine in a cat, however. If such a pathology is suspected, the veterinarian conducts additional laboratory tests. In this case, the specialist determines the level of urea and urea nitrogen in the blood. In the presence of renal failure, these indicators will also go off scale.

Sometimes the cause of elevated blood creatinine in a cat is also some kind of liver problem. In addition, such a pathology in an animal can also occur when the body is dehydrated. In this case, the cat additionally increases the density of urine.

Actually, creatinine itself is not a toxic substance. Poorly behaving animal at his elevated content feels precisely because of problems with internal organs.

Diagnosis of diseases: what should be considered?

The causes of elevated blood creatinine in cats can be different. But the following factors can affect the level of this substance in the body of an animal:

• obesity;
• severe deficit energy substances in the body;
• diet with low content high-calorie foods;
• deviations in mass for this particular breed;
• extreme age marks of the animal.

When diagnosing a cat's health status and determining the level of creatinine, all these factors must be taken into account.

Symptoms

With an increase in the level of creatinine in the blood to 200 µmol / liter, the behavior of the animal, most likely, will not change in any way. The cat's condition will begin to worsen after this figure reaches 300 µmol / liter. At elevated creatinine the cat may in this case be observed the following symptoms:

• lethargy and weakness;
• diarrhea and vomiting;
• pallor of mucous membranes;
• cessation of urination or reduction in the amount of urine excreted;
• decreased appetite.

From the mouth of a cat with a high content of creatinine, urine usually smells bad.

The level of this substance in the blood of animals can be determined and not only in µmol / liter. Sometimes it happens, for example, that the owners are interested in whether the cat has a chance with creatinine up to 1500 mg / dl. This level corresponds to 250-300 µmol/liter. Since creatinine is not a very accurate indicator, it is still premature to talk about the development of PN in this case. The cat's blood should first be checked for urea content. Perhaps this indicator is associated with dehydration or liver pathology.

The prognosis for a cat with 1200 mg/dl creatinine may not be too bad either. This level indicates a relatively slight increase in this substance in the body. But it is imperative to diagnose renal failure in this case.

What you need to know

Sometimes the level of creatinine in the blood of a cat remains normal. But such a disease as renal failure, the animal still develops. This usually happens when a cat, for example, picked up on the street, is too exhausted. With insufficient feeding in animals, the volume of muscle mass can sharply decrease. As a result, the level of creatinine in the blood also falls. With renal failure in such an animal, the amount of this substance will be close to normal. But in fact, the content of creatinine for such a condition of the animal can be considered elevated in this case.

How are tests taken?

Veterinarians can determine the amount of creatinine by examining how whole blood and plasma or serum. The choice of analysis method depends primarily on what laboratory equipment is available in the clinic.

Blood sampling to determine the level of creatinine can be done at any time of the day. Bad feeling a cat is also usually not an obstacle to this procedure.

Disadvantages of diagnostics

Normally, creatinine in a cat's blood should be equal, therefore, 40-130 mmol / liter. But unfortunately, this indicator in such pets can actually fluctuate very widely. In addition to the pet's weight and activity, it can be influenced by the nature of nutrition, breed characteristics, etc. In addition, the very sensitivity of creatinine as an indicator of the state of the excretory system is considered not too high. Even with a 50% decrease in kidney filtration due to pathology, the level of this substance in the blood can remain almost normal.

Urea indicators

As already mentioned, with elevated creatinine in a cat and suspected kidney failure, doctors often perform additional laboratory tests. The urea level for cats is considered normal at 6-12 mmol/liter. With its increased content, the animal will experience, among other things, the following symptoms:

• lethargy and weakness;
• unsteadiness of gait;
• ammonia smell from mouth;
• mouth ulcers;
• weight loss;
• food refusal.

What to do with high content

The level of creatinine in the blood of cats is determined, of course, only in a veterinary clinic. In accordance with the results obtained, the doctor gives the owner of the animal all necessary recommendations and, if necessary, appoint additional tests. Do research on the percentage of urea in the blood at high creatinine a cat is a must. Renal failure is very serious illness. And leave the animal without medical care in the presence of such a pathology, of course, it is not worth it.

Cat blood test: decoding

On the level of creatinine in the blood of a cat, veterinarians usually conduct studies in case of suspicion of kidney disease. If the cause of the animal's discomfort is not yet clear, the clinic performs complex analysis. Its decryption usually looks like this:

1. HCT - hematocrit. An excess of this substance can signal dehydration of the animal's body or, for example, the development of diabetes in it. The norm of this substance in the blood of a cat is 24-26%;
2. HGB is hemoglobin. An elevated level indicates dehydration, a lower level indicates anemia, damage to the hematopoietic organs, starvation. The normal level of hemoglobin in a cat's blood is 80-150%.
3. WBC - leukocytes. An increase in readings may indicate leukemia, inflammation, oncology, a decrease in a viral disease, illness bone marrow, radioactive damage. The normal level of leukocytes for cats is 5.5-18.0 × 109 / l.
4. RGB - erythrocytes. Elevated levels can indicate dehydration, lack of oxygen, and in some cases kidney and liver disease. A reduced content indicates blood loss, anemia, inflammation. The normal level is 5.3-10 × 1012 / l.
5. ESR - erythrocyte sedimentation rate. An increase in the level may indicate liver and kidney disease, heart attack, oncology, poisoning, shock. There is no reduced ESR. Normally, this figure is 0-13 mm / h.

Also, when performing laboratory tests, the blood of an animal can be checked, for example, for indicators such as eosinophils, neurophils, monocytes, platelets, lymphocytes, etc. Bad tests blood in a cat is, of course, a reason to diagnose the disease and prescribe the appropriate treatment.

How to lower blood creatinine levels

This indicator is usually brought back to normal with the help of medications. For example, a veterinarian can prescribe treatment with high creatinine in a cat using Hofitol. The drug is human, and it is sold in ordinary pharmacies. Most often, these tablets are given to animals 2 times a day for half. But, of course, only a veterinarian should prescribe the medicine and choose the dosage.

In chronic renal failure, the treatment of the animal can only be symptomatic. The answer to the question about whether the cat has different kind medications. They are usually prescribed by a veterinarian in combination with other means to improve the condition of a pet and prolong its life.

Causes of kidney failure

Actually, PN itself is not actually a disease. Renal failure is primarily a syndrome of dysfunction of the excretory system. This problem can be caused by:

• poisoning and intoxication;
• vasculitis, pyelonephritis in the kidney area;
• stenosis renal vessels;
• diabetes mellitus in older cats.

Animals may also have a hereditary predisposition to kidney failure. When buying an expensive cat, its pedigree is therefore worth asking.

Consequences of kidney failure

It is imperative to treat this pathology, and immediately. Kidney failure is a very insidious disease. Creatinine itself is a safe substance. But toxic nitrogenous bases, the content of which also increases with PN in the blood of cats, destroy vitamins and many others useful material. In an animal with renal insufficiency, serious violation water-salt balance and

In case of severe damage, suffers endocrine function adrenal glands of a pet. In the body of a cat, the synthesis of glucocorticoids stops. This eventually leads to hypokleemia and reduced insulin sensitivity, which in turn can lead to the development of diabetes.

Symptoms of kidney failure

So, the cat has elevated creatinine. What does this mean, we found out. Of course, such tests usually cause the owner to worry about the condition of the animal's kidneys. Only a veterinarian can diagnose deficiency. But the owner of the animal elevated readings creatinine, of course, you need to watch your pet yourself. Symptoms of kidney failure in particular are:

• constant unquenchable thirst;
• increased amount of urination;
• clarification of urine;
• occasional refusal to eat.

Occasionally, an animal with PN may experience nausea and vomiting. By itself, this symptom does not indicate any disease. Cats specifically eat grass and various inedible things to cleanse the stomach. But in combination with other symptoms, this symptom can also indicate the presence of PN.

In the later stages, symptoms of deficiency may include:

• cat's inability to swallow food;
• anorexia and dystrophy;
• defeat nervous system due to toxins
• the appearance of protein and blood in the urine of the animal;

Very common in cats with kidney failure late stages the pressure is greatly increased. And this, in turn, can lead to blindness due to rupture of blood vessels in eyeball.

Acute Deficiency Treatment

In this case, therapy is usually aimed at correcting the electrolyte balance and acid-base disorders. The most common cause of acute renal failure is the poisoning of the animal. Of course, in this case, measures are taken to remove toxins from the body of a pet.

Quite often, with acute renal failure, veterinarians perform a procedure such as dialysis for cats. In this case abdomen the animal is cut and a tube with a special liquid is inserted into it. During the time spent in the cat's body, toxins from his body pass into this solution. This procedure is prescribed only for animals with serious electrolyte imbalances in the body.

How to treat chronic insufficiency

sharp shape You can still try to cure PN somehow. But most often in cats, chronic renal failure occurs. Unfortunately, the disease is incurable. Giving an animal with such a pathology special food and medicines, most likely, will have to be done for the rest of his life. There are no specific treatment regimens for this disease. The approach to each animal should be in this case individual.

Treatment in the presence of CRF in animals is symptomatic. For anemia, for example, Erythropoietin can be administered to a cat, sodium bicarbonate is used for acidosis, etc. In case of intoxication, drugs are usually administered to pets through a dropper.

If the creatinine in the blood of a cat is elevated and he is diagnosed with PN, the owner will definitely have to keep the pet on special diet assigned to his pet by a veterinarian. Usually, with kidney failure, doctors recommend that the owner of a four-legged pet buy ready-made professional food for him, specially designed for animals with such a disease.

It is almost impossible to cure CKD. But the owner of such a cat is quite capable of alleviating his suffering and improving the quality of his life by relieving severe symptoms. In any case, you should not despair and give up with such a diagnosis. It is only necessary to strictly follow the recommendations of the veterinarian, and then the animal will delight the owners with its presence for many years to come.

Chronic renal failure (CRF) visible clinical manifestation of impaired renal function caused by the irreversible death of nephrons in progressive kidney disease. This is usually observed with the loss of 75% of the functional mass of the kidneys and is manifested by a multi-symptom complex, reflecting the participation in this process of almost all organs and systems of the sick animal. In retrospective studies dominated by cats older than 7 years, neither sex nor breed predisposition was found.

Chronic renal failure (CRF)

Are determined elevated level urea, urea nitrogen and creatinine. The determination of blood creatinine is more important than the determination of urea, because the level of creatinine is not affected by diet or the level of protein breakdown.

It is also possible to determine the speed glomerular filtration: determine the volume and concentration of creatinine in the urine per day and correlate with the level of creatinine in the blood serum.

Symptoms of lack of appetite are observed at a urea level of more than 25 mmol, with a urea content of 40 mmol (normal 5-10 mmol), the animal will experience severe depression and anorexia.

Insufficient excretion of restrictive phosphorus leads to an increase in its level in the blood, while the level of calcium falls (with moderate CRF, the level of phosphorus is not more than 2.1 mmol, with severe CNP, more than 3.2 mmol).

Release of calcium from bones high level phosphorus leads to mineralization of soft tissues. Most cats with CKD have hyponatremia and/or hypokalemia, hypoalbuminemia, or hyperamylasemia. Non-regenerative anemia, hypokalemia. Isosthenuria, urine density 1008 and below.

The following picture prevails: non-regenerative anemia caused by a decrease in the production of erythropoietin by the kidneys and a decrease in the life span of circulating erythrocytes, leukocytosis with lymphopenia and thrombopenia.

Isosthenuria (osmolarity is usually below 1015), pH changes to the acid side, proteinuria, inactive urinary sediment, rarely glycosuria.

Increased echogenicity of the renal parenchyma, blurring of the boundaries of the cortical and medial layers, a decrease in the size of the kidneys.

A decrease in the size of the kidneys is determined by less than 2.5 times the length of the body of the second lumbar vertebra (L-2). If obvious hyperparathyroidism is observed, then a decrease in bone density, especially in the upper jaw, and soft tissue calcification are seen.

Differential Diagnosis

Differentiate from acute renal failure (ARF), prerenal and postrenal uremia.
With acute renal failure, there is no anemia, polyuria and polydipsia, a decrease in the kidneys, but there are anamnestic signs of an extrarenal underlying disease.

Glomerulonephritis is combined with severe proteinuria, while the size of the kidneys is normal, with a tendency to edema.
With pyelonephritis in the analysis of urine active urinary sediment, pyuria. The kidneys may be irregularly shaped, dilatation of the pelvis and ureters on ultrasound. Leukocytosis of the blood.

From polydipsia without urea retention, Diabetes mellitus, Dibetes isipidus centralis and renalis, psychogenic craving for drinking.

Histopathological examination of the kidneys (biopsy) with acute renal failure is observed:

• acute tubular necrosis
• acute inflammation

• a significant part of the normal parenchyma is replaced by fibrous tissue,
• extensive tubular atrophy,
• basement membrane calcification,
• chronic inflammation (chronic interstitial nephritis),
• glomerulosclerosis

Treatment

Most common kidney disease in cats is diagnosed without a clear idea of ​​its cause, so treatment is aimed at eliminating the main symptoms. Goals of the therapy:

• maintaining the quality of life,
• slowing down the degeneration of damaged kidneys and the progression of chronic renal failure,
• reduction of azotemia,
• decrease in proteinuria
• reduced risk of hypertension.

Anorexia and dehydration: intravenous or subcutaneous injection of solutions of 0.18% sodium chloride + 4% dextrose. The required volume of injected solutions is calculated from the need for 50 mlkg24 hours
Systemic hypertension: ACE inhibitors or blockers calcium channels(enalapril 0.25-0.5 mg kg per os, every 12-24 hours, amlodipine 0.10-0.25 mg kg per os, every 24 hours).
Metabolic acidosis: sodium bicarbonate 8-15 mg kg orally every 8-12 hours.
Hypokalemia: Hartmann's solution, Panangin.

Hyperphosphatemia: low phosphorus diet (Royal Canine renal, Hill's kd, Eucanuba renal, Pro Plan NF), phosphorus content not more than 0.6% of daily ration. The introduction of drugs that bind phosphorus in the gastrointestinal tract aluminum hydroxide 30-60 mg kg per day with food.

Weight loss: high-calorie diet, appetite stimulation with various taste stimulants, parenteral nutrition, nasoesophageal tube
Proteinuria and hypoalbumemia: ACE inhibitors enalapril 0.5 mg kg per os, every 12-24 hours - reduce protein excretion by the kidneys when they are damaged. A diet rich in omega 3 polyunsaturated fatty acids.

Immune suppression: annual vaccination and protection of the animal from potential sources of infection.
Decreased appetite and vomiting: protein-reduced diet with urea level above 40 mmol, H2 receptor antagonists (famotidine 0.5 mg kg per os, every 12-24 hours, metoclopramide 0.2-0.4 mg kg per os, subcutaneously, every 6-8 hours.

Anemia: with hematocrit below 18% erythropoietin 25-100 units, subcutaneously 1-3 times a week, ferrous sulfate 5-20 mg/day per os.

conclusions

1) CKD is the irreversible progressive destruction of kidney tissue as a result of diseases that, in the absence of dialysis or kidney transplantation, lead to the death of the patient.
2) In cats with CKD symptoms may be absent until the glomerular filtration rate becomes very low.
3) The consequence of CRF is a violation of the metabolism of water and sodium, calcium and phosphorus, anemia.

Literature

1. Di Bartola, S.P., Tarr, M.J. and Benson, M.D.: Tissue distribution of amyloid deposits in Abyssinian cats with familial amyloidosis. J. Comp. Pathol. 96:387-398, 1986.
2. Candler E.A., Gaskell C.J., Gaskell R.M. Feline medicine and therapeutics, Blackwell Science, 1994, p. 118-121
3. Douglas Slatter "Small animal surgery", Saunders, 2003, p. 1562-1616
4. Paula Hotston Moore "Fluid therapy for veterinary nurses and technicians" Butterworth Heinemann, 2004, p. 11-41
5. Nephrology. Ed. E. M. Shilova. M.: GEOTAR-Media, 2007, p. 599-612.

Blood chemistry

A biochemical blood test is laboratory method research used in veterinary medicine, which reflects the functional state of the organs and systems of the animal's body.

A biochemical blood test in cats requires some preparation of the animal for the procedure. Blood is taken from a pet on an empty stomach before diagnostic and therapeutic procedures. A needle is inserted into the vein through which blood is taken. The resulting material is collected in a test tube and sent along with the referral to the laboratory.

Biochemistry of bloodin cats may help with:

Making a final diagnosis

Determining the prognosis of the disease - the course and its further development,

Disease monitoring - monitoring the course and results of treatment,

Screening - detection of the disease at the preclinical stage.

Spectrum biochemical parameters big enough. The main indicators for the study are: enzymes(molecules or their complexes accelerating (catalyzing) chemical reactions in living systems) and substrates(the initial product converted by the enzyme as a result of a specific enzyme-substrate interaction into one or more end products). Decryption biochemical analysis blood in cats is based on the data of the studied enzymes and substrates.

The main indicators characterizing the enzymatic activity of the body are:

1. Alanine aminotransferase (ALT)- is found mainly in the cells of the liver of cats and, when damaged, enters the bloodstream. Therefore, with an increase in ALT, they speak of acute or chronic hepatitis, liver tumors, fatty degeneration of the liver. This enzyme is also found in the kidneys, cardiac and skeletal muscles.

2. Aspartate aminotransferase (AST)- high activity of this enzyme is typical for many tissues. Determination of AST activity is used to detect disorders of the liver and striated muscles (skeletal and cardiac). When the cells of the above tissues are damaged, their destruction occurs, which may indicate necrosis of liver cells of any etiology (hepatitis), necrosis of the heart muscle, necrosis or injury of skeletal muscles.

3. Alkaline phosphatase (AP)- the activity of this enzyme is found mainly in the liver, intestines and bones. The total activity of alkaline phosphatase in the circulating blood of healthy animals consists of the activity of liver and bone isoenzymes. Therefore, in growing animals, the bone AP isoenzyme is increased. But in adult animals, this increase indicates bone tumors, osteomalacia, or active healing of fractures.

An increase in the level of alkaline phosphatase in the blood is also the result of a delay in the release of bile (cholestasis and, as a result, cholangitis). However, in cats, the half-life of circulating ALP is only a few hours, limiting the value of ALP as a marker of cholestatic disease.

The ALP isoenzyme responsible for the activity of the latter in the intestine is found mainly in the small intestine. At the moment, it has not been sufficiently studied in cats; therefore, when the activity of intestinal alkaline phosphatase changes, one can indirectly judge pathological processes GIT.

In cats, there is often an increase in the activity of alkaline phosphatase and other liver enzymes in hyperthyroidism, and a decrease in the latter in hypothyroidism.

4. Amylase - refers to digestive enzymes. Serum alpha-amylase is primarily derived from the pancreas and salivary glands. Enzyme activity increases with inflammation or obstruction of pancreatic tissue, which may indicate pancreatitis, acute hepatitis. However, in cats, traditional amylase tests to detect pancreatitis are not of sufficient diagnostic value. Also, an increase in amylase activity is observed in acute and chronic renal failure.

Other organs also have some amylase activity - thin and colon, skeletal muscles. Therefore, an increase in blood amylase may indicate intestinal intussusception, peritonitis.

For clinical trial The following substrates are of primary importance:

1. Total protein. Proteins are necessary components of all living organisms, they are involved in most of the life processes of cells. Proteins carry out metabolism and energy transformations. They are part of cell structures- organelles secreted into the extracellular space for the exchange of signals between cells, hydrolysis of food and the formation of intercellular substance.

Diagnostic value this indicator quite widely and can indicate complex processes occurring in the body. An increase in total protein is observed with general dehydration of the body, infectious and inflammatory processes. Loss (decrease) occurs in diseases of the liver, gastrointestinal tract, kidneys, the result of which is a violation of protein absorption, as well as in the depletion of animals, alimentary dystrophy.

2. Albumin. Serum albumin is synthesized in the liver and makes up the majority of all serum proteins. Since albumin makes up a large part of the total blood protein, they have a close relationship with each other. Thus, an increase or decrease in total protein occurs due to the albumin fraction. Therefore, these indicators have a similar diagnostic value.

3. Glucose. In animals, glucose is the main and most versatile source of energy for providing metabolic processes. Glucose is involved in the formation of glycogen, nutrition of brain tissue, working muscles.

Glucose is the main indicator for diagnosing diabetes mellitus in animals, which develops as a result of an absolute or relative deficiency of the hormone insulin. This, in turn, provokes the development of hyperglycemia - a persistent increase in blood glucose. There is also a significant increase in blood glucose levels in chronic kidney disease.

An increase in glucose can also be observed under various physiological conditions: stress, shock, physical activity.

Hypoglycemia (low glucose levels) may result from acute necrosis of the liver or pancreas.

4. Urea - end product of protein metabolism in animals. Found in blood, muscles, saliva, lymph.

AT clinical diagnostics determination of urea in the blood is usually used to assess the excretory function of the kidneys. So, a significant increase in the level of urea is observed in violation of kidney function (acute or chronic renal failure). Shock or severe stress. Low values observed with insufficient intake of protein in the body, severe liver disease.

5. Creatinine - end product of protein metabolism. Most of the creatinine is synthesized in the liver and transported to the skeletal muscles and then released into the blood, is involved in the energy metabolism of muscle and nervous tissues. Creatinine is excreted from the body by the kidneys with urine, so creatinine (its amount in the blood) is an important indicator of kidney activity.

High creatinine is an indicator of a rich meat diet (if there is an increase in the blood and urine), kidney failure (if there is an increase only in the blood). The level of creatinine also increases with dehydration, muscle damage. Low level observed with reduced consumption of meat, starvation.

6. Bilirubin total. Bilirubin is one of the intermediate breakdown products of hemoglobin that occurs in macrophages of the spleen, liver, and bone marrow. With obstruction of the outflow of bile (blockage bile ducts) and some liver diseases (for example, hepatitis), the concentration of bilirubin in the blood, and then in the urine, increases. A decrease in the level of bilirubin occurs in diseases of the bone marrow and anemia.

Gerke A.N., Researcher"Clinical and biochemical laboratory of SPbGAVM"; Semenova T.A., practitioner veterinarian

Conference materials: "Veterinary Medicine - Theory, Practice, Education" 2006

The kidneys perform excretory (remove metabolic products), regulatory (maintains the volume and composition of fluid in the body) and endocrine functions (renin, erythropoietin, etc.). Due to acute and chronic diseases kidneys, more often in older animals, chronic renal failure (CRF) can develop - a violation of homeostasis caused by the irreversible death of nephrons with progressive kidney disease. There are some metabolic features in cats that should be considered when examining and treating kidney disease.

Etiology and pathogenesis. CRF is a condition in which the glomerular and tubular functions of the kidneys are disturbed, uremia develops, resulting in a change in water-electrolyte and osmotic homeostasis. Regardless of the cause of kidney damage in chronic renal failure, irreversible structural changes occur, leading to the loss of nephrons. Although the reasons for the development of uremia are diverse, morphological changes in the kidneys in chronic renal failure are of the same type: fibroplastic transformation of the renal parenchyma is expressed with the replacement of nephrons with connective tissue and subsequent wrinkling of the kidneys. The progressive process of sclerosis of the renal parenchyma is due both to the activity of the underlying disease (glomerulonephritis, interstitial nephritis, etc.) and to hemodynamic disorders of inflammatory origin: the influence of arterial hypertension and hyperfiltration in the remaining glomeruli.

The most frequent causes of chronic renal failure are: glomerulonephritis, ICD, hydronephrosis, diabetes mellitus, hypercalcemia, amyloidosis, polycystic kidney disease and many others. Renal failure may result from acute renal failure or from a cumulative effect resulting from repeated minor injuries.

With the development of acidosis, the ability of the damaged kidney to excrete hydrogen ions and restore bicarbonate is limited. The development of renal acidosis is facilitated by the loss of bicarbonates in the urine, due to a violation of their reabsorption, which occurs as a result of damage to the renal tubules, a decrease in the activity of carbonic anhydrase and the progression of azotemia, in which the ability to remove toxins from the body is impaired.

Uremia is non-infectious cause immunodeficiency, so patients are predisposed to the development of severe infections. Suffering a lot cellular immunity and neutrophil function.

Uremia significantly affects the functioning of the gastrointestinal tract. uremic ulcerative stomatitis and gastroenteritis are indirect results of high concentrations of urea in saliva and gastric juice. Bacterial urease breaks down urea into ammonia, which causes mucosal damage.

Since the hormone calcitriol is synthesized by the proximal tubules, the weakened kidneys do not synthesize enough of it, partly due to hyperphosphatemia, and partly due to renal failure associated with cell loss in the proximal tubules. Deficiency of calcitriol causes impaired calcium absorption in gastrointestinal tract, leads to hypocalcemia and compensatory secondary renal hyperparathyroidism, which is a fairly late sign of CRF.

The synthesis of erythropoietin is another endocrine function of the kidneys. Erythropoietin is necessary for normal erythropoiesis and its deficiency, caused by insufficient synthesis in altered kidneys, inevitably leads to anemia, which is non-regenerative in nature. Additional causes of anemia are gastrointestinal bleeding due to uremia.

The inability of the kidneys to catabolize a number of polypeptide hormones leads to their excess with subsequent endocrine and metabolic disorders. Gastrin, insulin, glucagon and growth hormone - these hormones accumulate when there is insufficient renal catabolism. Excess glucagon and growth hormone in some patients with uremia leads to insulin resistance and prolonged postprandial hyperglycemia (impaired glucose tolerance).

Hypertension is a major complication of kidney disease as a result of activation of the renin-angiotensin system.

Clinical manifestations chronic renal failure (CRF) is usually non-specific. In the clinical picture of chronic renal failure, the general clinical symptoms associated with intoxication - anorexia, vomiting, weight loss, weakness, lethargy, polyuria, polydipsia, pruritus(sometimes exhausting). A decrease in the concentration function of the kidneys is manifested by the syndrome of polyuria - polydipsia (refers to early manifestations HPN). In the later stages, non-regenerative anemia, uremic gastritis, ulcerative stomatitis, halitosis, and dehydration develop. Secondarily, the "rubber jaw" syndrome may develop, which is associated with secondary hyperparathyroidism (long-term hyperphosphatemia and hypocalcemia).

Diagnostics based on laboratory results. Instrumental methods also have prognostic value (reduction in the size of the kidneys on the radiograph and with echography, an increase in echogenicity, polycystic - according to ultrasound).

To confirm the diagnosis and detect metabolic disorders special value represent laboratory tests. An increase in the concentration of urea, nitrogen, creatinine in the blood are the most important signs of kidney failure. An increase in the level of these metabolites in the blood is caused by a decrease in the depuration (cleansing) function of the kidneys. Of all the indicators of nitrogen metabolism, the concentration of creatinine is the most indicative, because. it, being a component of residual nitrogen, is excreted in the urine by glomerular filtration and is not reabsorbed in renal tubules. The content of creatinine in the blood of healthy animals is quite stable, does not depend on the intake of proteins with food and the intensity of their breakdown processes in the body, in contrast to the concentration of urea. Urea is not the primary uremic toxin (it is non-toxic on its own), but its serum concentration correlates with the severity clinical signs uremia. The degree of hyperphosphatemia changes, as a rule, in parallel with the growth of urea, which is a prognostic unfavorable sign.

Depending on the degree of decrease in glomerular filtration rate and the concentration of creatinine in the blood in cats, we distinguish 3 stages of CRF:

initial stage(blood creatinine concentration up to 250 µmol / l) - accompanied by a decrease in appetite, periodic vomiting, dry skin may occur. It is important to remember that the first signs of kidney failure appear only after the loss of 65% of the functioning renal tissue(C. Brovida, 2004).

conservative stage(blood creatinine concentration 252 - 440 μmol / l) - apathy, depression, moderate polyuria develop, clinical signs of dehydration may appear, some animals experience vomiting, diarrhea (hemocolitis is possible).

AT terminal stage (blood creatinine concentration greater than 440 µmol/l) anemia is observed (often signs of anemia go unnoticed due to severe dehydration and hemoconcentration, so hematocrit and hemoglobin remain within the normal range). The end stage of CRF is evidenced not only by high performance components of residual nitrogen in the blood, but also hypocalcemia (up to the development of seizures), symptoms of uremic encephalopathy, hyperphosphatemia, a picture of decompensated uremic acidosis (Kussmaul breathing), interstitial edema lungs. With prolonged severe azotemia, life is impossible without dialysis or kidney transplantation.

At biochemical research serum of cats with CRF, we paid attention to interesting fact: in addition to high concentrations of protein, urea, creatinine and often phosphorus, the level of amylase and sometimes lipase in the blood also increases, without clinical manifestations pancreatitis. In this case, in addition to the clinical signs characteristic of CRF (polyuria, polydipsia, loss of appetite, mild anemia) in cats, not diarrhea and vomiting, characteristic of pancreatitis, but constipation, leading to coprostasis, are observed. At the same time, we paid attention to the absence of vomiting, pain in the epigastric region, body temperature was within the physiological norm. It is also interesting that the increase in amylase activity often begins with an improvement in the general condition, restoration of appetite, a decrease in the concentration of urea and creatinine in the blood serum, which, obviously, explains the absence of vomiting.

We hypothesized that an increase in serum amylase activity could be caused by a decrease in amylase excretion by filtration (macroamylasemia) or increased amylase reabsorption in damaged renal tubules. To assess the excretory function of the kidneys, some quantitative studies of urine and blood serum were carried out. 3 groups of animals were formed - cats and cats aged from 4 to 12 years. The first group included animals without signs of renal failure (the concentration of creatinine in the blood does not exceed 140 µmol/l), the second - animals with a latent (initial) stage of renal failure, the third - with a conservative stage of CRF. In blood samples, the concentrations of hemoglobin, creatinine, urea, phosphorus, and amylase activity were determined; in urine samples, relative density, protein, creatinine concentrations, and amylase activity were determined. For ease of interpretation, urinary protein-creatinine ratios were calculated (to correct for proteinuria) and the ratio of urinary creatinine concentration to serum creatinine concentration was determined. The results of the study are shown in table 1.

Table 1. Some indicators renal function in cats.

Thus, it was found that regardless of the activity of amylase in the blood and the viability of renal function, its activity in the urine of cats is extremely low and uninformative. Therefore, it is impossible to evaluate the activity of pancreatic cell cytolysis processes (pancreatitis, pancreatic necrosis) by urine studies in cats, unlike in humans. An increase in blood amylase activity in renal failure is possibly associated with increased absorption of amylase from the intestine due to coprostasis and increased permeability of the intestinal mucosa caused by mucositis. We believe that in this case, an increase in amylase activity, apparently, is not related to the direct effect of uremia on the pancreas, since an increase in amylase is often observed after the patient is stabilized and the conservative stage of CRF is transferred to a latent or non-azotemic one. I would like to point out that after symptomatic therapy and the elimination of coprostasis in most animals, amylase decreased to normal.

Studies have shown that with the progression of CRF in cats, significant reduction concentration function of the kidneys without significant proteinuria (as occurs with acute renal failure). Apparently, the rapid progression of signs of dehydration in cats with CRF is associated with this.

Treatment. Since CRF is a violation of homeostasis caused by the irreversible death of nephrons in progressive kidney disease, it must be understood that a complete recovery is impossible. Of great importance is the impact on the factors that exacerbate chronic renal failure, causing an additional, often reversible, decrease in glomerular filtration. These factors include infection urinary tract, overdose of saluretics and antibiotics, hypovolemia, hyponatremia, hypokalemia, hypercalcemia. It is necessary to control the water, electrolyte, salt regime. Early restriction of protein and phosphorus in the diet significantly slows down the progression of CRF, favorably influencing glomerular hyperfiltration. It is necessary to treat systemic hypertension, which occurs as a result of renal failure (ACE inhibitors, if necessary, diuretics, sodium restriction in the diet).

To reduce the severity of azotemia in the conservative stage of chronic renal failure, enterosorbents can be used. Correction of violations of phosphorus-calcium metabolism is important. Under the control of the level of calcium and inorganic phosphate in the blood serum, calcium carbonate and antacids that bind phosphates are administered orally. With the progression of anemia caused by chronic renal failure, recombinant erythropoietin preparations are successfully used - replacement therapy they noticeably improve red hematopoiesis. It is important to monitor the course of CKD with regular blood and urine tests.

It must be remembered that additional risk factors for the development of end-stage renal failure are a decrease in circulating blood volume, electrolyte disturbances, hypo- or hypertension, fever and sepsis. Therefore, in such patients, the appointment of nephrotoxic drugs (gentamicin, etc.), general anesthesia and surgical intervention can provoke an exacerbation of chronic renal failure with the development of the terminal stage and the death of the patient. In this regard, if CRF is suspected (age over 6 years, signs of exhaustion, pallor of the mucous membranes, a history of polyuria / polydipsia for several weeks or months, frequent vomiting, etc.), it is recommended to conduct blood tests to rule out renal failure. Only after obtaining information about the viability of the excretory function of the kidneys, it is possible to perform general anesthesia or prescribe potentially nephrotoxic drugs.

With the development of the terminal stage of chronic renal failure, measures developed in the treatment of acute renal failure in the stage of anuria are carried out. In human medicine, chronic hemodialysis, hemosorption and plasmapheresis are treated. We hope that these basic methods of stabilizing patients with severe renal failure will also be available to veterinary medicine.

In conclusion, we can say that timely diagnosis of kidney disease significantly increases the life expectancy of cats with CRF, only special studies help establish correct diagnosis and to adjust the treatment (ultrasound, biochemical and clinical analyzes blood, urinalysis).