Veterinary medicine deciphering the clinical analysis of urine in a dog. Video - Collecting tests from cats and dogs. Normal hematological parameters of dogs

The day has come when your beloved dog got, in a clinical setting, a urine test. And you, having received the result and looking at a beautiful form, where some names and numbers are written in a column, you understand ... that you don’t understand anything! In order to understand what the analysis testifies to, some transcripts are given below. With their help, you will be at least a little, but "in the subject." But it is worth knowing that this article is purely educational in nature and is by no means a method of making a diagnosis. Only a professional veterinarian can determine the correct, meaningful diagnosis and apply treatment to your dog.

Dog urine color

A yellow color is considered normal, which is determined by the saturation of substances that are dissolved in the animal's urine. Deviation from the normal appearance is a light or dark yellow color. If there was a sharp change in color, for example, to black or red-brown, then this indicates a serious illness. Turbidity should be understood as a large amount of bacteria or salts.

Reaction

Under the reaction of urine is meant the level of acidity. It depends on how and what the animal eats. If the diet consists mainly of meat food, then the urine will show an acidic reaction, if vegetable, then alkaline. A mixed diet will show a weak acid reaction, which is considered normal.

Relative density

It is determined by comparing the specific gravity of water with the specific gravity of urine. It characterizes the ability to concentrate urine by the animal's kidneys, i.e. shows how well the kidneys are working. Normal urine specific gravity values ​​range from 1.02 to 1.035.

Chemical analysis of dog urine

Chemical analysis evaluates how much bilirubin, protein, ketone bodies, urobilinogen and glucose are contained in the urine.

Amount up to 0.30 g / l is considered the norm. An increase in the amount of protein in the urine means that some changes in the body are occurring in the dog, such as a chronic infection or destructive processes in the kidneys.

The urine of a healthy dog ​​should be glucose-free. If it is present, then a violation of the flow of glucose filtration should be suspected, which is a consequence of acute renal failure, or diabetes mellitus.

We will not explain what ketone bodies are, but you should be aware that in a single urine test, they are not found in a healthy dog. The presence of ketone bodies in a urine sample may indicate gross metabolic disorders, including starvation.

Simply put, these are ordinary bile pigments. The urine of a healthy dog ​​does not contain them. If there are any, they suggest liver damage or a violation of the movement of bile.

Dog urine sediment studies

The urine sediment contains organic elements (another name for organized sediment) and inorganic elements (salts or unorganized sediment). Hematuria - the presence of red blood cells in the urine, characterizes diseases such as damage to the urinary tract (for example, cystitis).

The presence of hemoglobin

Hemoglobinuria is the content of hemoglobin in the urine, which is caused by intravascular destruction of red blood cells. The color of urine, at the same time, becomes coffee. If there are many leukocytes in the urine, then it can be concluded that the kidneys are inflamed or the urinary tract is affected by an infection (urethritis).

Epithelial cells are always found in the sediment of dog urine. Norm - if when viewed through a microscope, no more than 5 pieces are visible. Epithelial cells have a different nature of origin. There is a squamous epithelial cell that enters the urine from the vagina and does not carry any diagnostic information. And if a lot of transitional epithelium has appeared, then this indicates inflammatory actions occurring in the prostate gland, bladder, ureters, and even the possibility of new formations in the urinary tract.

inorganic elements

These are mainly salts that can precipitate as crystals, or as amorphous compounds. The salt content is highly dependent on the acidity level of the urine. Under normal conditions, the urine in the bladder is sterile. Microbes enter the urine from the urethra and their number should not exceed 10,000 pcs in 1 ml. If there is such an excess, then your pet has a urinary tract infection.

How to take a urine sample from a dog

We remind you that the material is collected in a sterile plastic container, which can be purchased at any pharmacy.

For analysis, at least 5-10 ml of urine is needed, but 20-100 ml is better, since diagnostically important cellular elements may not get into a small amount of urine. For analysis, it is desirable to collect an average portion of urine, but even some elements of the urethra, external genital organs, etc. can get into it. In order to minimize such errors, it is advisable to thoroughly toilet the external genital organs before collecting urine (especially in dogs) , do not allow wool, sand, filler, feces, insects and other foreign matter to enter the sample. Collected urine is not subject to long-term storage. In case of urination disorders, urine can be collected from the floor with a pipette or syringe (this should be reported to the doctor). It is IMPOSSIBLE to collect urine with cotton wool or a rag, because. all the basic information - cells, salts, etc.) will remain on the cotton wool / rag, which will distort the result of the analysis.

Collection of urine from a bitch

Previously, at home, a flat tray or saucer is prepared for urine collection. It must be thoroughly washed with water without detergents and poured over with boiling water. On the street you need to take with you a prepared tray, a container for urine and a second person - an assistant. One person holds the dog on a leash, and the second person, at the time of urination, puts a tray under the stream of urine and takes the middle portion of urine.

Collection of urine from a dog

You can take a container for urine with you outside and a second person - an assistant. To collect urine, you can use the container itself or it is very convenient to use a ladle (ladle) to collect it, substituting it for a stream of urine and then pour it into the container. One person holds the dog on a leash, and the second person, at the time of urination, puts an open container (ladle) under the stream of urine and takes the middle portion of urine. If the animal does not want to urinate in the substituted container, you have to use a condom. To do this, use a condom for ultrasound. In two opposite places near the elastic, you need to make small cuts and thread the ropes. The condom is put on the dog, and the ropes are tied on the back. Then urine can be poured into a container.

Liquid gold… What do you think the ancient healers called it? Perhaps honey? No. This is the "nickname" of urine. That is how it was called in all the great schools of healing of antiquity. And this is not accidental, since even the appearance of this liquid can tell a lot about the health of the patient, whether it be a person or an animal. Color is especially important. It can vary from golden to brown and even black. Since dark urine in a dog is a hallmark of many dangerous pathologies, we will try to uncover this issue in more detail.

The normal color of a dog's discharge is yellowish. The easiest way to compare it with a shade of fresh straw. The best way to accurately determine the color is to pour urine into a glass beaker and place it against a white piece of paper.

Now let's talk a little about physiology. As you know, urine is a normal physiological "waste" of the body, which is obtained after filtering and cleaning the blood by the kidneys. Normal urine is sterile and may change color depending on what your pet has recently eaten or drunk. By the way, why is yellow her normal color? Everything is simple. Urine contains urobilin, a derivative of bilirubin. By the way, the latter compound is very toxic, and therefore its excretion by the kidneys is a vital process for the whole organism.

The intensity of the yellow color in normal, light-colored urine indicates the concentration of the latter. Simply put, the intensity of the shade indicates "wateriness". "Diluted" urine will be almost colorless, while highly concentrated urine becomes bright yellow, amber, or honey-colored. Minor changes happen every day, and there is nothing wrong with that.

But if your pet's urine has changed color dramatically, and this effect has been going on for several days, you need to contact your veterinarian as soon as possible. Not only the dark color of urine in a dog can be a sign of illness! In some cases, even completely transparent urine can indicate pathology.

Read also: What is paralysis of the larynx in dogs

The main causes of discoloration of urine

What if your dog's urine is dark yellow? In principle, this is almost the normal color of dog discharge. If the urine has acquired such a shade after a long walk or workout, especially when the latter took place on a sunny day, this may indicate a mild degree of dehydration. Just give your pet plenty of water to drink.

Much worse when the urine has acquired an orange tint! Unlike dark yellow, this color is not physiological. In many cases, such a “juicy” transformation indicates serious problems with the liver (jaundice). However, not only about her:

So the conclusion is simple: if your pet's urine suddenly turns orange, take him to the clinic immediately. There you need to quickly do a blood test and find out exactly why the urine has changed its color.

Other color options

Red or pink urine is often due to a urinary tract infection. But it's not always so bad. Hematuria is very typical for the postoperative period, and this is not considered a pathology. Of course, only in cases where the red color is observed for only a couple of days. If the urine has turned dark red, you should call your veterinarian immediately anyway, as such metamorphoses are highly likely to indicate serious internal bleeding.

In addition, redness of the urine may be due to trauma. For example, if your dog fell seriously or was hit by a bicycle, his kidneys could well be damaged. In most cases, this is relatively "normal", but if the bleeding continues for several days, the intensity of the red color increases and the dog is lethargic, this is a serious reason to contact the veterinarian.

Read also: Coma in dogs - causes and symptoms of pathology

As we have already mentioned, many factors can influence the color of urine, and not all of them can be classified as pathological. In particular, the color of the discharge often depends on the treatment that the dog is undergoing. Some drugs can turn urine into a color analogue of an orange: take the same nitrofurans, often used in the treatment of cystitis and other inflammatory pathologies of the urinary system.

About haze

And what does a strong turbidity of urine indicate, even if it has a normal straw color? Most likely, this indicates the presence of cystitis, urethritis, nephritis, vaginitis, and other pathologies of the genitourinary system, up to cancer. If urine retains this appearance for more than a couple of days, we advise you to contact a specialist. This is especially true for those cases when the dog does not eat.

The danger of all inflammatory pathologies of the urinary system is that they can cause stagnation of urine. This is fraught not only with its turbidity and other “tricks” with color, but also with the absorption of metabolic products into the blood. We are talking about uremia, a severe condition in which the nervous system of the animal is affected, numerous neurological phenomena and seizures are observed.

By the way, let's briefly return to the beginning of our article. Remember what we said about completely clear urine? For dogs, "crystal" purity of urine is uncharacteristic. This may indicate poor kidney function that does not secrete urobilin, or your pet's polydipsia. Simply put, this happens in cases where the dog constantly and continuously drinks. This behavior often indicates problems with the thyroid gland, adrenal glands, or indicates some kind of poisoning. Well, or the dog just overate salty.

Shades of brown and black

Dark brown urine is a reason for your dog to visit the veterinarian immediately. If it is not possible to take the dog to the clinic, call a specialist at home. Nothing good can be expected from this color. The fact is that a brown or brown shade of urine indicates the appearance of myoglobin in its composition. This is a special protein of muscle tissue, and it appears only in cases where the muscles for some reason began to break down.

Dogs are prone to many dangerous diseases that may not manifest themselves for a long time, so for the timely detection and successful treatment of the disease, it is necessary to analyze the dog's urine.

Why do you need to take a urine test on your dog?

If the animal refuses to eat, it is inactive, sad a lot and does not rejoice at the arrival of the owner - this should be a cause for serious concern. Otherwise, the disease may go too far.

The analysis of the studied material is especially relevant for dogs older than 6 years. In older animals, the resource of all systems and internal organs is already worn out, so it is advisable to conduct a professional examination of the dog every year.

To prevent major problems with the health of the dog is possible only with the help of highly professional specialists of veterinary clinics. If laboratory tests are taken on time, the veterinarian will be able to keep the condition of the animal under control and, if necessary, prescribe the correct treatment.

What manifestations should disturb the owners

• The dog often has an urge to urinate. You should be wary if the pet leaves behind puddles in the living quarters. In this case, you should not punish the pet because he is probably not able to control himself. Apparently, he developed a serious illness.
• If the animal's urine is cloudy, with a disgusting odor, dark in color with blood or purulent inclusions, this most likely indicates problems in the kidneys. In the presence of such a disease, poor appetite and high fever are noted.
• Sometimes the dog stops urinating or pisses not in a jet, but in small droplets - this also signals poor kidney function.
• If a dog wants to eat or drink more often, but loses weight, he most likely has diabetes. The animal often urinates, and its hind limbs become numb.

In order for the veterinarian to be able to help the animal, he will need urine for laboratory testing. The owner must be aware of how to properly collect material for research, and what may be needed (what devices).

Tools needed to collect urine:

• A glass / plastic container with a lid - in which the analysis is taken to the laboratory.
• To collect urine, a clean tray or other improvised devices will do.
• If the dog refuses to go outside to pee or for some reason it is not possible to correctly take and collect the analysis from the animal, use a children's urine bag.
• It is also possible to collect with a clean diaper with a waterproof coating.
• Use protective gloves to prevent urine from getting on your hands.

Before using the containers, they must be thoroughly washed and dried. It is not recommended to use household detergents, as they can affect the chemical composition of urine. To disinfect the container, you can use soda, but after that it must be thoroughly rinsed under running water.

The best urine for analysis is the one that was collected in the morning, and animal urine is no exception in this case. It is best to collect material for analysis early in the morning, while the dog has a full urinary bladder and has not yet eaten.

The collected biomaterial must be delivered to the veterinary clinic no later than two hours later, otherwise changes will occur in its composition and the results will be distorted. If it is not possible to immediately collect the analysis, then there is no need to repeat attempts during the same day. The procedure should be postponed until the next morning.

Algorithm of action when taking urine

Many owners have no idea how to take urine according to the rules. It is almost impossible to get a dog to urinate in a jar. In fact, it is not difficult to collect dog tests, the main thing is to have the skills.

Rules for collecting urine for males

For a walk, you need to take a specially purchased disposable container.

• Dogs are quite suspicious, so try to make sure that the dishes for collecting urine do not catch their eye in advance. Otherwise, the animal will have fear, and it will simply try to sneak away from its owner. To prevent this from happening, you should put a leash on the cop and go for a walk with her to the place to which she is most accustomed.
• You can't let your dog go for a walk. Otherwise, as soon as the dog decides to pee, you will not have time to bring the container. It is not necessary to rush to the animal sharply, otherwise the dog will be frightened and the attempt will be unsuccessful.
• In order not to miss the moment, it is necessary to constantly be behind the dog during the walk. As soon as the pet lifts its hind paw, you need to do everything possible to carefully collect the urine.

When you get home, wash your hands thoroughly and treat them with an antibacterial agent.

How to collect urine from bitches

A clean bottle of ordinary water will do here. It needs to be cut in a certain way. As soon as the bitch wants to urinate on a walk, you need to substitute a bottle under the jet along the cut line. You can use a flat container.

For analysis, you need from 20 to 100 mm of urine.

There are other ways to collect urine:

• Using a plastic or metal catheter pre-lubricated with glycerin. During the manipulation, the bitch must stand. The genitals of the animal must be cleanly washed. It is necessary to open the labia and insert the catheter into the urethra.
• Urine can be collected by puncture. A pet is injected with a neuroleptic, laid on its back, and the bladder is probed. Then a needle is injected into the urethra at an angle of 45 degrees and the urine is simply easily sucked out with a syringe.
• catheterization technique. Immediately before the procedure, the catheters are sterilized and lubricated with petroleum jelly or glycerin. The dog must be laid on its side and the catheter inserted with a rotational movement into the urethra. Urine is drawn into a syringe and poured into a sterile sealed jar.

If the owner does not know how to take a urine sample from a dog, you should seek the advice of a veterinarian. The composition of the analysis can be influenced by the following factors:

• climatic conditions (air humidity, temperature);
• physiological (type of feed, presence of estrus, pregnancy);
• pathological (stress, infectious diseases, invasion).

Scientists conducted research on clinically healthy dogs. As a result, they managed to calculate the indicators that are present in urine and reflect the balance of work of all organs and systems of the animal body.

The composition of urine and the limits of the norm

The basis of urine is water. Ideally, these figures should be 97-98%. The components included in its composition:

• organic,
• inorganic.

The dog's urine should be light yellow or yellow (depending on the food), not cloudy and without a pronounced odor.

Urine analysis in a dog: the norm in the table

Decryption

1. Protein. Sometimes protein can be found in the urine. This is not always a departure from the old norm. This happens with an unbalanced diet or with excessive stress on the body.
2. Glucose. The doctor will determine the carbohydrate metabolism of the animal. Ideally, carbohydrates should be fully digested. But if there are too many of them, then a certain part of them will always be excreted in the urine.
3. Bilirubin. Elements of bilirubin indicate liver diseases.
4. Ketone bodies. The presence of ketone bodies, coupled with high blood sugar, is a sign of diabetes.

With a long fast or if there is a large amount of fat in the animal's food, the indicators may be normal.

Microscopic research methods

After some time, the urine settles and a precipitate forms in it.

organic sediments:

• The presence of erythrocytes indicates a disease of the organ system that forms, accumulates and excretes urine.
• Leukocytes - the norm is 1 - 2. If the number of leukocytes exceeds these figures, we can safely talk about kidney pathology.
• In the urine sediment there are always epithelial cells. This indicator is especially pronounced in females.
• A high percentage of the number of cylinders is a sign of abnormal kidney function.

Inorganic precipitates:

• When the acidity of urine is above normal, then it contains a lot of uric acid, potassium sulfate and calcium phosphate. This indicates possible tumors, pneumonia, uric acid diathesis, and fever.
• If the urine of an animal is brick-colored, this is a confirmation of such diseases as: glomerulonephritis, kidney failure.
• Calcium oxalate - is in the urine in a small amount. When the oxalate index is higher than normal, this is a manifestation of diabetes, pyelonephritis or calcium pathology. When plant foods predominate in the dog's diet, the presence of calcium carbonate in the urine is the norm.
• Fatty acids indicate an atrophic change in the kidneys.

Bacteriological analysis

If from 1000 to 10000 microbial bodies are detected in 1 ml of female urine, this is the norm. For males, these figures indicate inflammation of the urinary organs. This analysis is necessary to subtitrate the effect of antibiotics that will subsequently be used for treatment.

Neoplasms and crystals. If crystals of tyrosine or leucine are found, one can safely testify to pathologies caused by leukemia. The presence of cholesterol indicates neoplasms in the kidneys or dystrophic processes occurring there.

Analysis for the presence of fungi. At a certain temperature of analysis, microscopic fungi grow. In a normal analysis, they should not be present. But with prolonged use of antibiotics and in the presence of a disease such as diabetes, the painful microflora is activated.

Urine analysis for fungi can be carried out using test systems - these are special strips adapted for veterinary diagnostics and in a laboratory.

In some cases, the primary analysis made using the test system may deviate from the norm in one direction or another. In this case, there is no reason to panic. It is necessary to conduct repeated analyzes at a veterinarian that has a license to perform work. Any veterinarian can decipher a urine test.

Almost any disease of a dog can be cured. It is important to monitor the health of the dog and, at the slightest suspicion, contact a specialized medical institution.

conclusions

In order for therapy to be successful, you need to have the right research results on hand. With the help of urine analysis, not only the disease is detected, but also differential diagnosis is carried out. There should not be any inaccuracies, otherwise the doctor will prescribe the wrong treatment.

Indicators that are considered "norm" are averaged. You can not discount the gender, age, individual characteristics of the dog, the diet and the medications used.

Chervyakova Anna Alekseevna
laboratory assistant

General clinical examination of urine is one of the most frequently prescribed laboratory tests. Based on the results of this analysis, one can judge the state of the organs of the urinary system and the effectiveness of the urinary (it is performed by the kidneys) and urinary (the ureters, bladder and urethra are responsible for it) body functions, indirectly about the state of other body systems.

A very important step in the study is the correct collection of urine for analysis.
It is important to remember that no more than 2 hours should pass from the moment of urine collection to the end of the laboratory test.
Otherwise, you run the risk of getting false results, since when stored for more than 2 hours, the properties of urine change dramatically.

General clinical analysis of urine is carried out according to the following parameters:

• physical properties
• Chemical properties
• microscopic examination.

The study of the physical properties of urine
The physical properties of urine are examined by organoleptic methods, that is, as a result of assessing the appearance of urine using our senses, namely vision and smell.
Every attentive owner can, and even must, independently monitor the slightest changes in the process of urination, quantity, color, transparency, smell of urine your pet, so that in time, sometimes even before the deterioration of the general condition, seek help from a doctor.
As you understand, this assessment is purely subjective and only indirectly indicates the problem.
Therefore, if you notice that your animal has changed urine or the process of urination has been disturbed, you should definitely, without delay, consult a doctor to find out the reasons and take the analysis to the laboratory for professional research.
The study of the chemical properties of urine and microscopic examination of its sediment provides the doctor with objective results, is carried out only in a laboratory, using laboratory methods and equipment.

Study of the chemical properties of urine

Relative density (specific gravity) shows the amount of dissolved particles in the urine and has different values ​​in healthy cats and dogs, on average, normal values ​​range from 1.010 to 1.025.
It is very important to obtain data on the relative density of urine before starting treatment, especially before infusion therapy and the appointment of diuretics (diuretics).
A decrease in density to 1.007 and below and an increase in density over 1.030 indicate that the concentration and dilution ability of the kidneys is only partially preserved.

pH of urine is an indicator of the concentration of free hydrogen ions. Healthy dogs and cats can have a pH of 5.5-7.5.
The reasons for the change can be an abundant intake of meat, vomiting, diarrhea, chronic urinary tract infections, cystitis, pyelitis and other reasons.

Protein in the urine - proteinuria accompanies almost any pathology of the kidneys. This figure must be interpreted together with the relative density.
Normally, in healthy animals, the protein does not increase by more than 0.3 g / l. To more accurately determine the severity of protein losses, more quantitative methods are required - a daily study of protein in urine, the ratio of protein to creatinine in urine.

Glucose in the urine (glucosuria) of healthy animals is absent. The appearance of glucose in the urine may indicate the most common disease in animals, diabetes mellitus. In this case, you should always measure the level of sugar in the blood.
Glucose can appear in animals under stress, especially in cats.
In addition to diseases of the pancreas, glucosuria appears with acute renal failure, glomerulonephritis, hyperthyroidism, and certain drugs.

Ketones in the urine (ketonuria) are not normally found. Ketonuria appears when there is a violation of carbohydrate, fat or protein metabolism.
Wasting, starvation, and diabetes are among the most common causes of ketones in the urine.
Also, ketonuria can accompany acute pancreatitis, extensive mechanical injuries.

Bilirubin in the urine (bilirubinuria). Dogs (especially males) may have low levels of bilirubinuria if the relative gravity of the urine is equal to or greater than 1.030.
Cats do not normally have bilirubinuria.
The most common causes of severe hyperbilirubinuria in dogs and cats are liver disease, bile duct obstruction, and hemolytic disorders. Weak bilirubinuria may be the result of prolonged fasting (anorexia).

Urobilinogen in the urine (urobilinogenuria). Physiological concentration in urine is 17 µmol/l. When using this test, it is impossible to determine the complete absence of urobilinogen.
Increased excretion of urobilinogen in the urine occurs with increased intravascular breakdown of erythrocytes (piroplasmosis, sepsis, DIC) and with chronic liver diseases.

Nitrites in the urine (nitrituria). The urine of healthy animals gives a negative test result. The detection of nitrites in the urine indicates infection of the urinary system.
But it should be remembered that in this test there is a possibility of obtaining a false negative result. Therefore, it is not possible to draw conclusions on the presence or absence of kidney and urinary tract infections only on the basis of this study.

microscopic examination
Some diseases of the kidneys and urinary tract are often asymptomatic. Therefore, a study of urine sediment under a microscope is carried out.

Epithelium. There are 3 types of epithelium in the urine sediment: squamous transitional and renal.
In healthy animals, the epithelium is not present in the urine. But a small amount of squamous epithelium is very common in urine samples entering the laboratory, and this, as a rule, is not a sign of pathology. It enters the urine from the mucous membrane of the external genital organs at the time of urination. But the appearance in the urine of transitional, and even more so of the renal epithelium, indicates serious damage to the kidneys, ureters, and bladder.

Leukocytes. Normal values ​​should not exceed 0-3 leukocytes per field of view. This disorder indicates inflammation and infection of the urinary tract. Stones and neoplasia are other common causes of high white blood cell counts in the urine.
Also, a large number of leukocytes can enter the urine from prepuce or vaginal discharge, in order to exclude these factors, it is better to take urine by cystocentesis, or try to collect an average portion of urine. Often leukocyturia is accompanied by bacteriuria.

red blood cells. The presence of red blood cells (hematuria, or blood in the urine) or their hemoglobin derivative (hemoglobinuria) is first determined by the test strip. The reaction to blood should be negative.
Regardless of the test strip readings, a microscopic examination of the urine sediment for the presence of erythrocytes is performed. Normal values ​​range from 0 to 5 RBCs per field of view.
Particular attention should be paid at what point in urination bleeding occurs.
Blood in the urine, regardless of urination, or most strongly at first, indicates damage to the urethra, prostate, or foreskin in male dogs or the uterus (vagina) in females.
Blood at the end of urination indicates damage to the bladder. If blood is present throughout the entire urination, then this can be caused by bleeding in any department.

cylinders. These are cylindrical sediment elements, consisting of protein and cells with various inclusions, which are casts of the renal tubules.
Normally, healthy animals may contain 0-2 hyaline cylinders in the field of view.
The presence of cylinders confirms kidney disease. The type of cylinders gives some information about the pathological process, the number does not correlate with the reversibility or irreversibility of the underlying disease.
Often, when casts appear in the urine sediment, proteinuria is also recorded and the renal epithelium is detected.

Slime. A small amount of mucus may be present in the urine of healthy animals. This is the normal secretion of the mucous glands of the urinary tract.
With a very high content of this secret in the urine, a large, viscous, mucous sediment is formed. Such changes are characteristic of cystitis.

Crystals (salts). Microscopic recognition of urinary crystals is an imperfect technique, as their appearance changes through numerous factors.
Many crystals in a small amount can be normal. For example, calcium oxalates, calcium phosphates, ammonium urates (especially in Dalmatians and English Bulldogs), bilirubin crystals in healthy dogs with concentrated urine.
A large number of crystals often makes one think of the presence of urolithiasis (stones). Animals with crystalluria do not always form stones (uroliths), and the identified crystalluria is not always an indication for treatment.

bacteria. In a healthy animal, the urine in the kidneys and bladder is sterile. Therefore, in the urine obtained by puncture of the bladder (cystocentesis), bacteria should not normally be present.
Bacteria in excreted urine may be the result of a urinary tract infection or contamination of the distal urethra and genitals by normal flora.
Very often there is a false increase in the number of bacteria in the urine due to improper collection in a non-sterile container and storage of urine at room temperature.
The presence of bacteria in the urine with a correctly taken sample allows diagnosing a urinary tract infection. In this case, a quantitative bacteriological urine culture is recommended to determine the significance of bacteriuria and determine the sensitivity of the detected bacteria to antibacterial drugs.

In dogs with chronic kidney disease, a baseline urinary protein-to-creatinine (UPC) ratio >1.0 is associated with a three-fold increased risk of uremic crisis and death.

The relative risk of adverse outcomes increases 1.5-fold for every 1 increase in UPC.

In another study in dogs, proteinuria correlated with the degree of functional impairment as measured by glomerular filtration rate; life expectancy of dogs with UPC< 1,0 в среднем была в 2,7 раза выше, чем у собак с UPC > 1,0.

In a prospective long-term study in cats without evidence of azotemia, proteinuria was found to be significantly associated with the development of azotemia within 12 months. Both proteinuria and serum creatinine have been associated with reduced survival in cats with chronic kidney disease. This pattern persisted in cats even at a UPC as low as 0.2-0.4.

Chronic proteinuria has been found to lead to interstitial fibrosis, degeneration and atrophy of the renal tubules. There is evidence that resorbed proteins and lipids have a direct toxic effect on renal tubular epithelial cells, causing inflammation and apoptosis. In addition, excessive breakdown of proteins by lysosomes leads to rupture of the lysosome and intracellular release of cytotoxic enzymes. Proteinuria can lead to an excessive increase in the load on the epithelial cells of the renal tubules. Protein casts cause blockage of the tubules, which leads to even more damage to the cells. Damage to the glomerular filter leads to reduced perfusion of the interstitial tubules, which causes cell hypoxia. Increased selective permeability of the glomerular filter increases the filtration of other substances, such as transferrin, further damaging the tubules.

Since proteinuria is associated with adverse outcomes, a thorough understanding of the optimal management of proteinuria in cats and dogs with chronic kidney disease is essential for the veterinarian.

Clinical assessment of proteinuria
An accurate assessment of proteinuria includes 3 key components: persistence, localization, and intensity. Persistent proteinuria is proteinuria that occurs 3 or more times at intervals of 2 or more weeks. For the implementation of adequate therapy, it is important to identify the causes of proteinuria in a cat or dog. Prerenal proteinuria occurs when there is an increased supply of low molecular weight plasma proteins to the normal glomerulus (examples: hemoglobinuria, myoglobinuria). Postrenal proteinuria occurs when protein is excreted in the urine due to exudation of blood or serum into the lower urinary or genital tract (examples: urinary tract infection, urolithiasis, neoplasia). It is important to make sure that proteinuria is not due to prerenal or postrenal causes, as the treatment of these pathologies differs significantly from the treatment of chronic kidney disease. Renal proteinuria of a glomerular or tubulointerstitial nature is one of the most characteristic forms of proteinuria in the treatment of dogs with chronic kidney disease. Functional proteinuria in dogs and cats is rare, or at least not well documented.

Once prerenal and postrenal causes of persistent proteinuria have been ruled out, the intensity of the disease determines whether the disease is glomerular or tubulointerstitial in nature. Intensity is assessed using urine protein quantitation (usually UPC, but urinary albumin concentration may also be used). After exclusion of prerenal and postrenal causes, it is recommended that UPC be assessed with a dipstick or sulfosalicylic acid test for each dog with persistent proteinuria. On the other hand, in cats, the UPC target for therapeutic intervention may be no more than 0.2. With such a low rate of proteinuria in a cat with chronic kidney disease and dilute urine, a test strip may be negative. For this reason, UPC testing is recommended 1-2 times per year for all cats with chronic kidney disease.

Table 1: Classification of proteinuria in cats and dogs with CKD according to the International Society for the Study of Kidney Disease

The International Kidney Society (IRIS) has recommended staging dogs and cats with CKD based on UPC scores (Table 1). Dogs with renal proteinuria and UPC > 2.0 usually have glomerular disease, while dogs with UPC< 2,0 может наблюдаться гломерулярная или тубулоинтерстициальная болезнь. У кошек гломерулярная болезнь встречается реже, но ее следует подозревать при UPC >1. Concomitant hypoalbuminuria is additional evidence for the presence of glomerular disease.

Suppression of the RAAS for the treatment of proteinuria
Since the driving force of the blood flow affects the transglomerular transport of proteins, changing the hemodynamics of the kidneys should be an effective way to reduce proteinuria. With this approach, the main target for reducing proteinuria is the renin-angiotensin-aldosterone system (RAAS). Drugs that target the RAAS include angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor antagonists (ARAs), and aldosterone receptor antagonists (Table 2). All RAAS inhibitors have antihypertensive properties, although most of them only slightly reduce blood pressure (ie, by 10-15%). In addition to the expected reduction in glomerular capillary blood pressure, these drugs appear to reduce proteinuria through several mechanisms. Similarly, the observed reduction in proteinuria is greater than would be expected based on the antihypertensive properties of these drugs alone.

Table 2: RAAS inhibitors used in dogs and cats with CKD

* Lower initial doses should be used in animals with stage 3 or 4 CKD, and in the presence of comorbidities that could potentially lead to dehydration or decreased appetite.
** Can be used alone or in combination with an ACE inhibitor.
*** As a rule, combined administration with an ACE inhibitor is recommended.
**** Recommended only for dogs with glomerular disease that have elevated serum or urinary aldosterone levels and are refractory to or intolerant of ACE inhibitors or ARBs.

RAAS suppression is considered the standard of care for dogs and cats with renal proteinuria when UPC is >0.5-1 and >0.2-0.4, respectively. RAAS inhibitors reduce proteinuria in animal populations, but the level of such effects in individual individuals may vary. In order to obtain the desired effect on proteinuria, selection of drugs or their combinations by trial and error may be required; for some animals, the required reduction may not be achievable.

UPC, urinalysis, systemic arterial pressure, and serum albumin, creatinine, and serum potassium (in fasted samples) should be monitored at least quarterly in all animals treated for proteinuric kidney disease. However, if new drugs are introduced or dosages of administered drugs are changed, such monitoring should be carried out more frequently. UPC, serum creatinine, serum potassium, and systemic blood pressure should be assessed 1–2 weeks after initiation or dose changes of an ACE inhibitor or ARB to confirm that recent changes in treatment have not resulted in a severe deterioration in renal function (i.e. , an increase in serum creatinine > 30%), an alarming increase in serum potassium, or hypotension (unlikely with these drugs).

Diurnal fluctuations in UPC occur in most dogs with glomerular proteinuria, with greater variability in dogs with UPC > 4. Changes in urinary protein are most accurately measured by assessing changes in UPC over time. Because dogs with UPC > 4 show a large diurnal variability in this parameter, consideration should be given to either averaging the values ​​obtained from a series of 2-3 UPC tests or measuring UPC in the urine pool from 2-3 samplings.

For most dogs and cats with proteinuria, ACE inhibitors are the treatment of choice, with a standard starting dose of 0.5 mg/kg every 24 hours. However, the ARA telmisartan may soon become a reasonable alternative as the drug of choice. For dogs, the ideal goal of therapy is to reduce the UPC to< 1 без неприемлемого ухудшения почечной функции. Поскольку эта идеальная цель для большинства собак не достигается, часто целью становится снижение UPC на 50% или выше. Степень до-пустимого ухудшения почечной функции будет отчасти зависеть от стадии ХБП у собаки. У собак с ХБП 1-й и 2-й стадии допустимо повышение креатинина сыворотки крови на 30% без изменения курса терапии. Целью лечения для собак с 3-й стадией ХБП является поддержание стабильной почечной функции, допуская лишь 10% повышение креатинина сыворотки крови. Если почечная функция ухудшается сверх этих пределов, могут потребоваться изменения в терапии. Собаки с 4-й стадией ХБП, как правило, не переносят снижение почечной функции, и любое ее ухудшение может повлечь за собой клинические последствия. В то время как для данной категории пациентов могут применяться ингибиторы РААС, начальные дозы и шаг возрастающих доз должны быть очень небольшими, а почечная функция должна внимательно отслеживаться; для поддержания исходно-го уровня почечной функции могут потребоваться изменения в терапии.

If the required decrease in UPC is not achieved, the plasma potassium concentration< 6, а любые изменения по-чечной функции находятся в пределах допустимого, дозировка может увеличиваться каждые 4-6 недель. Если целевое снижение UPC не достигнуто при максимальной дозе ИАПФ, следующим шагом будет добавление АРА. Альтернативным вариантом в случаях, когда у собаки наблюдается непереносимость ИАПФ, может быть применение АРА в качестве монотерапии.

hypertension
Persistent hypertension can cause damage to organs such as the eyes, brain, cardiovascular system, and kidneys. Left untreated, hypertension can cause worsening proteinuria and progressive kidney damage. RAAS inhibitors, as a rule, have a very weak antihypertensive effect, and their use leads to a decrease in blood pressure by only 10-15%. It is desirable to maintain blood pressure at a level< 150 мм рт. ст. Собакам с систолическим давлением крови >160 In addition to the administration of a RAAS inhibitor, additional antihypertensive therapy may be required. The first step in this case would be to increase the dose of the RAAS inhibitor. If this measure is ineffective and after reaching the upper dose limit, the next step should be an additional calcium channel blocker, usually amlodipine (0.25-0.5 mg/kg every 24 hours). In treated cats and dogs, systolic blood pressure should be maintained at > 120 mmHg. Art.

Diet
In chronic kidney disease in dogs, the intensity of proteinuria can be reduced by changing the diet, in particular, by changing the ratio of polyunsaturated fatty acids and protein content. Supplementing the diet with omega-3 polyunsaturated fatty acids or feeding a diet with a reduced omega-6/omega-3 ratio close to 5:1, as found in most pet foods on the market with kidney disease, is thought to alter the long-term course of kidney disease and reduces the intensity of proteinuria. It is a generally accepted fact that protein-modified food for animals with kidney disease reduces intraglomerular pressure, as well as the intensity of proteinuria and the production of uremic toxins.

Aspirin Therapy in Dogs with Proteinuria
Thromboembolism is a common complication of glomerular proteinuria. Therefore, for dogs with a UPC > 3, or with an appropriate serum albumin level< 2,5 г/дл часто рекомендуется применять аспирин или клопидогрел. Однако на сегодняшний день существует недостаточно свидетельств безопасности и эффективности этих препаратов для собак с гломерулярными заболеваниями.

Literature
1. Brown S, Elliot J, Francey T, Polzin D, Vaden S. (2013). Consensus recommendations for standard therapy of glomerular disease in dogs. J Vet Intern Med 27: S27-S43.
2. Jacob F, Polzin DJ, Osborne CA, et al. (2005). Evaluation of the association between initial proteinuria and morbidity rate or death in dogs with naturally occurring chronic renal failure. J Amer Vet Med Assoc 226, 393-400.
3.Jepson RE. Brodbelt D, Vallance C, et al. (2009). Evaluation of predictors of the development of azotemia in cats. J Vet Intern Med 23:806-813.
4. King JN, Tasker S, Gunn-Moore DA, et al. (2007). Prognostic factors in cats with chronic kidney disease. J Vet Intern Med 21:906-916.
5. Lees GE, Brown SA, Elliot J, et al. Assessment and management of proteinuria in dogs and cats: 2004 ACVIM forum consensus statement (small animal). J Vet Intern Med 19:377-385.
6. Syme HM, Markwell Pj, Pfeiffer DU, et al. (2006). Survival of cats with naturally occurring chronic renal failure is related to the severity of proteinuria. J Vet Intern Med 20:528-535.
7. Wehner A, Hartmann K, and Hirschberger J. (2008). Associations between proteinuria, systemic hypertension and glomerular filtration rate in dogs with renal and non-renal diseases. Vet Rec 162: 141-147.

Shelley L. Vaden,
College of Veterinary Medicine, North Carolina State University,
Raleigh, North Carolina, USA