home Audience 5 Types of kidney stones - classification, chemical composition, features of formation and treatment. Urolithiasis in cats

Types of kidney stones - classification, chemical composition, features of formation and treatment. Urolithiasis in cats

Moscow Veterinary Clinic "Alisavet"

ICD occupies one of the leading places in the structure of urological morbidity in animals.

Urolithiasis (urolithiasis) in cats and dogs - a disease manifested by the formation of stones in the organs of the urinary system.

Urolithiasis refers to polyetiological diseases with complex physicochemical processes occurring not only in the urinary system, but also in the whole organism, both congenital and acquired.

The causes of urolithiasis are not fully understood and not fully understood

The following factors are involved in the development of urolithiasis: Risk factors for the development of urolithiasis, a description of which can be found in the works of Hippocrates. Currently, they are divided into three main groups: demographic, external factors environment and pathophysiological. Urolithiasis is characterized by endemic distribution.

There are more than 200 known conditions that can potentially lead to the formation of stones in the urinary system.
For example:

physical inactivity (home lifestyle of cats and dogs)
hypoxia
taking a small amount of fluid (mixed food, various treats affect the animal’s fluid intake)
disruption of the regular normal flow of urine through the urinary tract
oversaturation of urine with salts
change in urine pH
the appearance of difficultly soluble salts
urinary tract infections
consuming foods with excess substances that promote stone formation
Stress, etc.

Modern urology has many ways to treat patients with urolithiasis. In human medicine, open methods of removing stones are increasingly used. They are inferior to the remote method shock wave lithotripsy and endoscopic treatment methods: contact endoscopic and through skin removal kidney and urinary tract stones. The introduction of new minimally invasive technologies has undoubtedly made a significant contribution to the effectiveness of urinary stone removal, minimizing the number of traumatic complications. However, none of these methods is a method of treating urolithiasis and does not guarantee complete recovery, and often introduces additional negative factors for the development of relapse of the disease.

Etiology and pathogenesis of ICD

One of the important reasons urolithiasis in animals is a violation water-salt metabolism. Metabolic (dysmetabolic) nephropathy unites a group of diseases in which metabolic disorders occur, accompanied by changes in the kidneys. These are toxic diseases such as shock, dehydration, drug injuries, electrolyte disturbances; chronic, hereditary and acquired (sugar diathesis, hypovitaminosis, hypervitaminosis) diseases.

Great importance There is also a change in the chemical composition of the blood that occurs with infectious diseases, intoxications, diseases of the liver and gastrointestinal tract (hepatitis, gastritis, colitis). Diseases of the glands play a role in the formation of urolithiasis internal secretion, such as the thyroid gland, parathyroid gland, pituitary gland.

Main hypothesis The basis of urolithiasis in animals (stone formation) is a decrease in the content of protective colloids in the urine. Under these conditions, a group of molecules is formed - a micelle, which can become the core of the future stone. Fibrin joins it, shaped elements blood, bacteria, remnants of epithelial cells and, finally, sparingly soluble salts when they are found in excess in the urine.

Stones form in the collecting ducts. If the urine is oversaturated with salts and the pH of the urine changes, then crystallization and retention of stones at the mouths of the tubules increases. Violation of urodynamics will contribute to the formation of large stones - single and multiple. The sizes of stones can vary from 0.1 to 10-15 mm or more, and their number sometimes reaches several hundred.

Urinary stones are observed, as a rule, in one of the kidneys (usually in the right) and only in 15-30% of patients are they bilateral. In the practice of the ALISA veterinary clinic over the past five years, this fact of the medical hypothesis has not been definitively confirmed. In the course of collecting data and summarizing the available material, we established the fact, as a rule, of bilateral formation of stones, in both kidneys at once. It is not uncommon for stones to form in the non-pelvis, not in the intracanalicular lumens, but in the intracapsular localization of calcinosis, which in turn complicates treatment; surgical treatment in such cases is completely excluded.

With sharp and frequent fluctuations in pH and uncontrolled use of litholytic (stone-dissolving) drugs, complex compositions, the so-called “coral-shaped” stones, are formed. Stones injure the kidneys and urinary tract, contribute to their infection, and further disrupt the outflow of urine.

Small stones located in the renal pelvis or ureter obstruct the outflow of urine from the kidney, causing its gradual expansion and subsequent death of the kidney tissue that produces urine.

Often large stones exist for a long time without causing significant damage.

The matrix theory can explain the process of stone formation. She claims there is protein composition some dead cell, then salts are deposited on it. The core of stones is always an organic substance, which can either be the material for the formation of the entire stone (cystine stones) or, as we note most often, only a matrix on which various salts are deposited.

Numerous factors contributing to the formation of stones can be divided into exogenous and endogenous, and the latter - into general (characteristic of the entire body) and local (directly related to changes in normal condition kidneys and urinary tract) Exogenous pathological factors include climatic, geochemical conditions, nutritional characteristics, etc. Temperature, air humidity, the nature of the soil, the composition of drinking water and its saturation with mineral salts play an important role. The nature of feeding of dogs and cats is of great importance, which in turn affects the composition of urine and its pH. Plant and dairy foods contribute to the alkalization of urine, meat – to its oxidation. Drinking water, oversaturated with lime salts, reduces the acidity of urine and causes an excess of calcium salts in the body. To the endogenous factors contributing to the emergence urolithiasis include hyperfunction of the parathyroid gland (hyperparathyroidism), causing disturbances in phosphorus-calcium metabolism. The presence of vascular abnormalities of the liver is important, usually in the form of shunts between the portal vein and the general venous system, which affects the synthesis of purines, resulting in increased formation of lactic acid. Local endogenous factors play an important role in pathogenesis - changes in the normal state of the kidney and urinary tract, primarily factors leading to stagnation of urine, impaired secretion and reabsorption of its constituent elements, and the development of uropathogenic infection. Inflammatory processes in the kidney also contribute to the process of stone formation. This is confirmed by studies that have established the presence of a number of microorganisms capable of breaking down urea, which leads to its alkalization and precipitation of salts - phosphates. Depending on the chemical composition of the salts that form stones in urolithiasis, they are distinguished:

Causes of the disease lower sections urinary tract in cats without urethral obstruction (statistics for 3 years)

Reason % percentage of cases

Idiopathic 64.2

Stone in the urinary tract 12.8

Stone in the urinary tract -

+ their infection rate 1.8

Urinary tract infection 0.9

Neoplasms 1.8

Anatomical deviation 9.2

Behavioral disorders 9.2

You can begin treatment for urolithiasis after establishing the nature of the accumulated salts, since inadequate dietary and therapeutic measures can contribute to the formation of complex stones.

Surgical removal of stones, as well as extracorporeal lithotripsy (crushing), do not provide recovery and do not eliminate the causes and conditions of stone formation. These methods are applicable in life-threatening situations, for example, when the ureter is blocked by a large stone, which cannot be eliminated by emergency conservative therapy and threatens the development of hydronephrosis and anemia.

An approximate algorithm for a doctor’s actions during an examination of an animal with a problem with the urinary system.

Contrast cysto and pyelography, cystourethroscopy

Laboratory diagnostics of OKA, General biochemistry + potassium, phosphorus, calcium

Urinalysis, if necessary, urine protein/creatinine ratio

Tank. Urine culture (centesis only)

Urine density using a refractometer only

In older cats, a T4 level is desirable

Treatment of urolithiasis should be comprehensive and individual.

The regimen should help restore the tone of the smooth muscles of the urinary tract. (avoid hypothermia). You should pay attention to regular bladder emptying.

Diet, pharmacotherapy and herbal medicine should be focused on the specific form of urolithiasis.

Treatment and prevention of struvite formation

A properly selected type of nutrition is one of the main, if not the main, requirements when organizing activities aimed at preventing the possibility of struvite formation in the lower parts of the urinary tract of animals.

Acidification of urine
Increasing the volume of urine and reducing its density (increasing the volume of urine also reduces the time it takes for crystals to pass through the urinary tract and, thus, the time for crystal growth)
Reduce intake of potential sources of struvite crystals in feed.

From theory and practice it follows that urine pH plays a significantly more important role important role for the formation of struvite than the amount of magnesium in the diet!!!

1a. Achieving a urine pH of 6.0-6.5 (measurement with a pH meter in fresh urine samples is advisable)

2a. Increase in urine volume and density (preferably to 1.035 and below)

3a. Reducing the consumption of minerals with food (magnesium - up to 20-40 mg, phosphorus - up to 125-250 mg for every 100 kcal of metabolic energy)

Good food and watch the pH. (this indicator varies greatly in cats), and then bring the urine pH to the specified values by adding one of the urine acidifiers (ammonium chloride or DL-methionine) to the food. Unlike dogs, struvite uroliths in cats are usually sterile. Therefore, antibiotics are prescribed to cats only if a urinary tract infection concomitant with urolithiasis is detected.

Among all types of urolithiasis, calcium oxalate urolithiasis ranks first in frequency of occurrence and is found in 75-75% of cases of the disease

Treatment and prevention of urolith formation from calcium oxalate

The pathogenesis of uroliths with calcium oxalate uroliths has been studied much less thoroughly than in the case of struvite. There is information obtained during clinical trials However, it should be kept in mind that in humans (unlike cats), calcium-containing stones (from calcium oxalate or calcium phosphate) in the urinary tract are more common.

In practice, we are increasingly encountering such problems in dogs and cats when urine pH, density, etc. are within normal limits, and stones in the bladder and kidneys form quickly. Upon examination of the stone, it turns out that it is calcium oxalate.

The crystal-forming agents are calcium and oxalate (oxalic acid).

Diets that stimulate urination and increase urine volume should prevent the crystallization of calcium oxalate in the urinary tract AFTER surgical removal uroliths.

Most often, the following metabolic disorders are detected with nephrolithiasis:

Hypercalciuria (36.7-60.9%) pathologically increased calcium content in the urine

Hyperuricuria (23-35.85) increased content uric acid in blood

Hypocitraturia (28-44.3%) Alkalosis, alkaline food excess

Hyperoxaluria - (8.1-32%) is one of the forms of anomaly in the metabolism of oxalic acid - oxalose.

Hypomagnesium (6.8-19%) Disorders of magnesium metabolism

As a rule, hypercalciuria is combined with hyperoxaluria. Moreover, the latter, along with hypocitraturia, is considered by some authors to be more important metabolic risk factors for the development of calcium oxalate urolithiasis than hypercalciuria.

We need to rethink the theory of urolith formation. For a very long time there has been no clear doctrine for the treatment of this pathology. We must try to study all the mistakes of previous years and understand the new direction in the etiology and pathogenesis of the disease.

KSD of the oxalate type usually appears in animals aged five years and older. It affects both sterilized and non-sterilized animals. Urine pH may be within normal limits or less than 6.0.

Tactics of allopathic medicine and its possibilities for at this stage do not give a visible healing result. This means that we should look for treatment options in other areas of pharmacology.

Homeopathy, naturopathy, herbal medicine, nosodetherapy, peptidotherapy are probably the right way out of this situation.

The Alice Veterinary Clinic is constantly working on the methodological implementation of new algorithms for the treatment of urolithiasis in animals.

New trends in the treatment of oxalate type uroliths.

Let's take a closer look at oxalate metabolism and the role of oxalobacter formigenes in the development of urolithiasis

In the human body, the contribution of nutritional oxalate to total urine excretion is 10-15%, the rest is endogenous oxalate.

The effect of dietary oxalates on urinary excretion of oxalic acid depends on calcium intake. Several population-based studies have found an inverse association between the amount of calcium intake and the risk of stone formation. So, according to a prospective study by Curhan G. et al. In a study of 45,000 men, low calcium intake (less than 850 mg/day) significantly increased the risk of kidney stones. The protective effect of calcium, according to the authors, is due to the fact that it binds oxalates and phosphates in the intestine, preventing their excess excretion in the urine, which contributes to the formation of stones. One of the common methods of preventing the formation of calcium oxalate stones is to reduce the amount of oxalate taken from food. However, dietary oxalate restriction may not be a reliable method of preventing the development of calcium oxalate urolithiasis. In this regard, some authors have proposed the concept of reducing the absorption of oxalate in the gastrointestinal tract. Recently, results have been obtained indicating the influence of the gram-negative obligate anaerobe Oxalobacter formigenes on the concentration of oxalate in the urine. The human body is characterized by two groups of strains. During its life, this microorganism uses exogenous oxalate as an energy source for its survival. The habitat of the anaerobes is the large intestine.

While not pathogenic for the human body, O. formigenes establishes a symbiosis using oxalates as a food source, as a result of which the absorption of oxalates in the lumen of the large intestine is reduced in humans. O. formigenes has a unique role in the daily catabolism of 70-100 mg of dietary oxalate. It has been proven that it is nutritional oxalate that is the substrate for maintaining the colonization of O. formigenes in the intestine when following a diet with reduced content calcium.

Data from various authors show a direct relationship between the level of urinary oxalate excretion and O. formigenes colonization. So Gnanandarajah J. et al. Fecal samples from healthy dogs and those with calcium oxalate urolithiasis were examined for anaerobe colonization. The results showed that colonization is present in 25% of dogs with urolithiasis, versus 75% in healthy dogs. The authors suggested that the lack of O. formigenes colonization is a predisposing factor for the development of calcium oxalate urolithiasis.

The experiment studied the effect of the microbe on the severity of the level of oxalate excretion in colonized and non-colonized rats, taking into account a calcium diet. The result also confirmed the hypothesis.

It is known that a number of antibiotics affect the preservation of O. formigenes.

The strain has demonstrated resistance to amoxicillin, ceftriaxone, doxycyline, gentamicin, levofloxacin, metronidazole and tetracycline.

But the antibiotic combinations amoxicillin/clarithromycin and metronidazole/clarithromycin destroy O. formigenes colonization.

Studying the colonization of the colon by this microorganism and its correction may improve the results of anti-relapse therapy for oxalate urolithiasis.

Veterinary clinic "Alisavet" Moscow

Data on O. formigenes was kindly provided by the State Educational Institution of Higher Professional Education “Military Medical Academy named after. CM. Kirov", Department of Urology, St. Petersburg. A.Yu. Shestaev, M.V. Paronnikov, V.V. Protoshchak, P.A. Babkin, A.M. Gulko.

02 February 2017

Definitions of the concept " urolithiasis disease"you can give a lot. To put it simply, its essence is this: due to metabolic disorders in the body of dogs and cats, formation occurs in the urine and urinary tract stones called uroliths or calculi.

Urine is a complex solution, which is a necessary medium for removing metabolic products from the body. Metabolic products (urea and creatinine), minerals (calcium, magnesium, phosphates), electrolytes (sodium and potassium), water are excreted in the urine; urine pH varies depending on homeostatic maintenance acid-base balance. Any deviations from the norm can lead to the development of urolithiasis in animals. Mechanical blockage of the urinary tract by stones is the cause of urolithiasis. Stones can form both in the kidneys and in the urinary tract, but the clinical symptoms of urolithiasis are associated specifically with urinary tract disease.

Diagnosis. Urolithiasis is diagnosed when stones are detected in fresh urine, in the bladder through ultrasound or x-ray examination and stones are detected during surgery to remove them. The presence of stones in urine that has stood for more than an hour does not give grounds to draw a conclusion about urolithiasis, since uroliths can precipitate as a result of natural chemical reactions.

Uroliths vary greatly in composition - from homogeneous (cystines) to a complex mixture of minerals and even minerals and proteins. They also differ in appearance- from soft deposits of sandy material (mucoid plugs), which are mainly seen in cats and consist of a protein-like shell filled with mineral content, to hard smooth or uneven stones, consisting mainly of minerals and small matrices. We will not describe in detail the properties of each of the stones; this is not the purpose of this article. Fellow veterinarians engaged in in-depth study of this problem can refer to the relevant manuals.

The formation of stones occurs for the following reasons:

1. If the concentration of urolith components in the urine is higher than the possibility of their dissolution and excretion without the formation of a crystal.
2. Some types of crystals are sensitive to urine pH. Thus, struvite is formed only in alkaline urine (PH> 7.0). Calcium oxalates are generally not sensitive to urine pH.
3. The formation of large crystals that can cause obstruction (blockage) of the urinary tract should occur very quickly, because When crystals form slowly, they are washed out of the bladder before they can cause harm.
4. The presence of a nucleus (base) to begin the formation of a large urolith. These may be cell remains suture material, bacteria and, according to some sources, viruses.
5. Some bacterial infections can contribute to the development of urolithiasis. Thus, some bladder infections contribute to the development of struvite-type urolithiasis in dogs (especially in bitches and puppies in the first year of life).

Clinical symptoms of urolithiasis

The presence of uroliths in the urinary tract can cause clinical symptoms that may or may not be noticed by the pet owner. This is especially true for cats, since they hide from their owners and their owners do not always see their act of urination. The main clinical symptom is the inability to urinate naturally or urination is difficult.

In this case, the animal often sits down (male cats, females) or raises its paw (males), tries to urinate, whines, cries, urine is released in drops, often with blood.

Palpation of the abdomen establishes the presence of a full bladder. This procedure in cats it can always be done, in dogs it can sometimes be palpated abdominal wall extremely difficult due to the tense powerful muscles of the abdominal wall.

There are several degrees of urolithiasis:

1. Subclinical urolithiasis. There may be no symptoms associated with the presence of uroliths in the urinary tract. Struvite, calcium oxalate and other calcium-containing uroliths are radioopaque and are visible on x-rays. A urine test may show elevated crystals and an abnormal urine pH. These uroliths are usually struvite and sometimes calcium oxalate. Calcium oxalate stones often have a very rough surface and can cause mild to severe symptoms of urinary tract inflammation, while smooth struvite or cystine stones often cause no clinical symptoms at all. Nephroliths rarely cause clinical symptoms other than hematuria until they move into the ureter, causing obstruction (blockage) and hydronephrosis.

2. Mild symptoms of urolithiasis:

Slight increase in urinary frequency
Mild hematuria - blood staining
Slight increase in urination time
Slight discomfort during urination
Increased licking of the genitals

3. Severe symptoms:

Pollakiuria - cats almost never leave their toilet, dogs constantly leak drops of urine
Urinary tenesmus (to be distinguished from constipation)
Severe hematuria - obvious blood in the urine
Severe discomfort when urinating - vocalization and obvious pain
On palpation, the bladder is greatly distended
Polydipsia/polyuria in case of secondary renal failure
General depression and anorexia

4. Symptoms life threatening animal:

Anuria (lack of urination)
Weakness/collapse
Dehydration
On palpation, the bladder may not be found if it has burst or is anuric (otherwise it feels like a dense mass)
Uremic halitosis may be detected
Vomit
Convulsions

For appointment adequate treatment The veterinarian must be able to assess the degree of development of urolithiasis.

Diagnosis of urolithiasis

Urolithiasis is confirmed:

Clinical symptoms
Palpation of uroliths in the bladder in dogs (in cats they are difficult to palpate)
Plain x-rays show radioopaque uroliths
Contrast radiographs for radiolucent and small (less than 2 mm in diameter) uroliths
Discharge of uroliths during urination (they can be collected in a net)

Radiography is necessary to determine radioopacity, location of deposition, number and size of uroliths. Usually stones are present in several places at once, so examination of all urinary tracts is necessary.

Rice. 1. Calcium oxalate crystals in urine

In cats, urolithiasis usually resolves with the formation of struvite (tripelphosphate), but recently there have been increasing cases of detection of calcium oxalates in the urine of cats and, even worse, urolithiasis mixed type, when at a neutral urine pH level both struvite and oxalates are present in the urine. Many veterinarians neglect laboratory diagnostics, relying on the prevalence of struvite in cats. I think this approach is wrong.

In dogs, KSD can occur with the formation of all known uroliths, therefore, laboratory visual determination of the type of stones for dogs is very important for prescribing treatment. A 10-mL sample of fresh urine sediment should be microscopically examined immediately after collection at body temperature because time, cooling, or evaporation of the urine may accelerate crystal precipitation and produce false positive or paradoxical results. Most common crystals have a typical appearance in urine, and if their number is large, one can judge the composition of the urolith or, according to at least, its outer layer.

Rice. 2. Struvite

Rice. 3. Struvite and red blood cells in urine

Treatment of urolithiasis

The choice of the correct treatment depends on the location(s) of the uroliths:

Kidneys- nephroliths are very difficult to remove surgically, unless they are concentrated in one kidney. Then nephrectomy (kidney removal) is possible. With nephrolitas, the development of postrenal renal failure is possible. Dissolution of struvite uroliths is possible by prescribing a special diet.

Ureters- uroliths located in the ureters can be successfully removed surgically, but one should remember about the possibility of developing postrenal renal failure.

Bladder- treatment depends on the type of uroliths. Struvite, urate, and sometimes cystine can be dissolved, and calcium oxalate and other calcium- and silica-containing uroliths can be removed surgically by conventional cystotomy (opening the bladder and removing stones).

Urethra- depending on how the uroliths lie, several types of treatment are used:

1) Manipulation - manual massage (often used for cats with sand plugs) or catheterization small polyurethane catheter (eg special catheter Jackson for cats or a medical subclavian catheter with a diameter of 0.6 - 0.8 mm).

Despite the fact that catheterization is often used to displace or break up uroliths in cats and some breeds of dogs, this method of treatment is the most dangerous for the following reasons:

it injures the tissue, which leads to fibrosis and scarring with subsequent narrowing of the urethra;
causes infection in the urinary tract.

2) Retrograde urethral lavage followed by dissolution (struvite, urate and cystine) or cystotomy (calcium oxalates, other uroliths containing calcium and silicon dioxide) is the only method of treating urethral urolithiasis.

Method of retrograde washing out of urethral stones

The animal is given general anesthesia or strong sedatives. Then they are executed the following actions:

Empty the bladder by cystocentesis (puncture of the bladder through the abdominal wall)
Through the rectum, fingers compress the urethra opposite the pubis, below the urolith (an assistant is needed for this)
A sterile catheter is inserted into the distal urethra
Secure the penile part of the urethra around the catheter
A sterile saline solution is injected into the catheter through a syringe.
When the intraluminal pressure reaches the desired point, the assistant removes his fingers and releases the urethra
Under pressure saline solution urolith returns back to the bladder
You can repeat the procedure several times

After retrograde lavage, recurrence of obstruction is very rare. This method, as a rule, is not used in cats; in males, this low-traumatic method is often recommended for use.

3) Urethrostomy used for males when manipulation or retrograde lavage has not been successful. A urethrostomy creates a permanent opening in the urethra. This method is used for recurrent obstructions of the penile urethra in cats and sometimes in males. Although this is the only method of treating animals with permanent urethral obstruction, it must be used with caution, because according to some data, in 17% of cases, urethrostomy in cats leads to postoperative urinary tract infection. In 10% of cats, urethrostomy and dietary changes also result in postoperative infection, while none of the cats treated with diet develop a urinary tract infection.

Dissolution

Struvite, urate and cystine stones can be dissolved. This is the only method for removing stones in animals with non-life-threatening urolithiasis. Dissolution is used for kidney or bladder stones. If a urinary tract infection is present, antibiotics are prescribed as part of treatment based on the results of urine culture and sensitivity testing. Treatment details are discussed below.

Struvite (magnesium ammonium phosphate, tripel phosphates). To dissolve struvite stones, it is enough to strictly adhere to special veterinary diets. They are represented quite widely on the Russian market; any veterinary clinic in Moscow and large Russian cities can offer a veterinary diet for your pet. We successfully use food from Purina (UR) and Hills (s/d, c/d).

These foods contribute to the acidification of urine, causing the dissolution of struvite. In addition, the increased sodium content in these diets stimulates diuresis (urination), which helps flush the bladder and speed up the elimination of accumulated salts. For urolithiasis not complicated by bacterial infections, treatment special diets brings positive results already 4-5 days after the start of treatment. It should be noted that contacting a veterinarian as early as possible and making an early diagnosis of urolithiasis promotes a speedy recovery of the animal and minimizes possible relapses of the disease. The owner's compliance with the animal's feeding regime is of great importance. THE ANIMAL CANNOT BE GIVEN ANYTHING ELSE EXCEPT A SPECIAL DIET!!!

Quality control of treatment is carried out by laboratory tests of urine and x-ray diagnosis of the presence of stones in the bladder. If there are no stones in the urine and in the photographs, the treatment is considered effective and the owner’s task in the future is a MANDATORY urine test at least once every six months. In our opinion, the optimal period for control testing is 3 months.

Laboratory assessment of urine pH, as well as the presence and analysis of urine sediment, determination of the type and quantity of urinary crystals.

Treatment of insoluble uroliths

-Calcium oxalates
Calcium oxalate uroliths are more common in certain breeds of dogs ( Yorkshire terriers and miniature schnauzers), and in last years they began to occur noticeably more often, especially in cats.
Unfortunately, this type of crystal is completely insoluble, and treatment of this type Urolithiasis is performed exclusively surgically, by removing stones from the bladder. Sometimes 3-4 operations per year are required if the intensity of oxalate formation is very high.
To prevent relapses, it is necessary to reduce the concentration of calcium and oxalates in the urine. Prevention is possible with special diets (Hills x/d, Eucanuba Oxalat Urinary Formula, etc.). I repeat. PREVENTION. But not the dissolution of oxalate stones!

-Calcium phosphates
Calcium phosphate crystalluria manifests itself in various forms: both amorphous (calcium phosphates) and calcium hydrogen phosphates (brushite). These minerals are often present in mixed uroliths along with struvite, urate, or calcium oxalate. Most calcium phosphate crystals (with the exception of brushite) are sensitive to urine pH and form in alkaline urine.
A medical protocol for dissolving these uroliths has not yet been developed, so surgical removal and prevention of hypercalciuria (as in the case of calcium oxalate urolithiasis), but not urine alkalinization, are recommended.

-Silicon dioxide (silicates)
Silicate uroliths are rare in dogs. They are called "Jack stones." The etiopathogenesis of these uroliths is not completely clear, however, it is believed that the risk of the formation of these stones increases if the dog eats soil or types of vegetables contaminated with soil (rutabagas, beets). Personally, I have never encountered this type of urolithiasis.
For clinical symptoms, the only treatment is surgical removal of stones, and as a preventive measure, it is recommended to ensure that the dog does not eat soil or vegetation contaminated with it.

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Introduction

Diseases of the lower urinary tract in cats are a serious problem in modern veterinary medicine for small animals. Most serious illness urolithiasis and associated complications, such as feline urological syndrome, are recognized. Urolithiasis is widespread, difficult to treat, persistently recurs, and is accompanied by high mortality rate. In cats, urolithiasis was first described at the beginning of the 20th century. Since then, it has been found that urological diseases occur in cats almost 3 times more often than in dogs, and 4 times more often than in humans. Although not all patients with urological disorders develop urolithiasis, the proportional mortality rate from urolithiasis is higher in cats than in humans and dogs. That's why this problem goes beyond veterinary medicine and becomes socially significant. Unfortunately, it is still not possible to give unambiguous answers to questions about the causes of the development of the disease and its pathogenesis. Although a lot of research has been devoted to urolithiasis in both humane and veterinary medicine. The large number of proposed various treatment methods, developed by scientists and practicing veterinarians, indicates not only the relevance of this problem, but also the dissatisfaction of many specialists with the results of treatment of urolithiasis in cats.

1. Definition of disease

Urolithiasis (UCD) is a chronic disease of all types of domestic and wild animals, as well as humans, characterized by a violation acid-base balance, mineral, protein, carbohydrate, vitamin, hormonal metabolism and the formation of single or multiple urinary calculi (stones) in the renal parenchyma, pelvis or bladder.

2. Etiology

The causes of urolithiasis can be:

· improper feeding (excess proteins and lack of carbohydrates, excessive feeding of fish containing large quantities of phosphates and magnesium salts);

· lack of vitamins A and D;

· sedentary lifestyle life;

· imbalance of acid-base balance of blood and lymph;

· breed predisposition;

· overweight;

· early castration;

· absence free access to drinking water (or poor water quality);

· urinary tract infections (especially streptococcal and staphylococcal).

Most of these reasons lead to metabolic disorders, in which there is excessive excretion of various metabolic products in the urine. For example, too early castration of a cat, accompanied by removal of the testes, can lead not only to hormonal imbalance, but also to narrowing of the already narrow urethra (urethra).

Cat breeds such as Persians have a genetic predisposition to urolithiasis, most of all to the formation of tripelphosphates. Neutered cats develop phosphate stones very quickly. In addition to Persians, long-haired Himalayan and Burmese cats are most predisposed to oxalate urolithiasis, which occurs in cats in approximately 25% of cases of urolithiasis. In general, KSD is detected in approximately 7% of cats admitted to veterinary clinics.

The urethra in cats is already quite narrow, and with a high content of fish and dairy products in the diet, crystals of phosphorus and calcium salts fall into the urine, which leads to spasms and urinary retention, with the subsequent occurrence of urinary tract infections and the development of acute renal failure. Males are most susceptible to UCD because their urethra is longer and narrower than that of females.

3. Pathogenesis and symptoms of the disease

With urolithiasis, various sparingly soluble salts accumulate in the kidneys and urinary tract, which causes a change in the acidity (pH) of the urine. These can be calcium phosphates, calcium carbonates, calcium oxalates, urates, as well as struvites (complex salts of ammonium, magnesium, phosphorus and calcium). Urates consist mainly of uric acid salts (on the surface of these stones there are spines that injure vascular walls, promoting inflammation), and phosphates - from calcium and magnesium phosphates. Phosphate and struvite stones form primarily in alkaline urine and grow very quickly. The most hard stones- oxalates, they are formed from salts of oxalic acid and are found, like urates, mainly in acidic urine. That is why normalizing the pH of urine leads to a slowdown in the formation of crystals and to the dissolution of existing ones. Carbonates are formed from salts of carbonic acid; they are soft, crumble easily and make up the bulk of sand in urine.

Uroliths are formed by the aggregation of mineral crystals. But urethral plugs consist of a protein matrix, which usually contains many mineral crystals. Both uroliths and urethral plugs can lead to inflammation and obstruction of the lower urinary tract.

Many uroliths in cats form in the bladder and can damage the mucous layer of the bladder. Depending on their size, uroliths can partially or completely block the bladder neck. And the urethra of cats can be blocked by both uroliths and urethral plugs.

Both blockage of the urethra and damage to its mucous membrane lead to stagnation of urine and the development of a secondary ascending urinary tract infection. As a result, catarrhal-purulent inflammation of the bladder (urocystitis) and renal pelvis (pyelonephritis) develops.

Symptoms The disease develops slowly - without obvious clinical signs, but the results of a urine test can give a fairly reliable prognosis. The pH of urine shifts to the acidic side for urates, oxalates and to the alkaline side for phosphates (the norm is 6.5 - 7), the density of urine increases. The animal refuses to eat, is depressed, and often licks the perineum. When the urinary tract is blocked, urinary colic is observed, the animal is restless, makes restless sounds when urinating, takes an unnatural position during urination (hunched over), stays in it for a long time, the pulse rate, breathing rate, and temperature increase. The animal experiences pain when its stomach is touched, goes to the toilet more often (or, on the contrary, can urinate anywhere), the amount of urine decreases, the urine may be cloudy or mixed with blood (hematuria), urination is difficult (or, conversely, very frequent and painful) or may be completely absent.

4. Diagnosis

Anamnesis. During the interview, it is usually possible to find out the main events in the development of the disease that preceded the patient’s admission to a veterinarian: when the first signs of the disease appeared, whether similar disorders occurred before, whether there is appetite, whether the patient takes water, the presence of vomiting and its intensity, what is the frequency of urination and the amount of urine excreted, the presence of blood in the urine, and the duration of urinary retention. In addition, it is appropriate to find out the structure of the diet, the method and amount of water taken, and the conditions under which the sick animal is kept. After collecting anamnesis, a general clinical examination begins.

Inspection. Many urologically ill cats, even in a new environment, at a doctor’s appointment, take a forced body position to urinate, sometimes excreting a small amount of cloudy or blood-tainted urine. A long-term disease is indicated by tousled, matted hair, sunken eyes, dry mucous membranes, and shortness of breath. In case of acute urinary retention, patients may exhibit severe neurological disorders: nystagmus, muscle twitching, forced position of the head - flexion of the occipito-atlas joint, "look from under the brows." Quite rarely, a full bladder is visually determined: a saggy asymmetrical abdomen. When examining the perineum, you can find dried fragments of urethral plugs, salt crystals, blood clots, and in cats “forced” paraphimosis.

Thermometry. General temperature the body of patients with urolithiasis is almost always within physiological norm 38-39.5ºC. However, if a urological syndrome develops, the patient’s body temperature steadily decreases and after 24-48 hours can reach critical levels of 34-35ºC.

Palpation. During palpation examination of a urological patient, it is necessary to determine the condition of the bladder. In most patients, the walls of the organ are moderately or severely painful and thickened. In the case of acute urinary retention, the pain increases, and the filling of the bladder rarely exceeds 350 ml, and the bladder fills a larger volume of the abdominal cavity. Palpation should be performed before and after the obstruction is relieved and the bladder is emptied. In cats and cats, it is extremely rare to palpate to determine the presence of uroliths in the bladder, but with luck, it is possible to identify foreign inclusions and the characteristic crepitus of stones. If the kidneys are accessible for examination (in obese animals the kidneys are less accessible for palpation), their location, shape, pain, and size are determined. This provides valuable information for excluding renal pathology not associated with feline urolithiasis. Palpation, in general clinical settings, it is possible to determine the degree of dehydration and hemomicrocirculation disorders in urological patients.

Urethral examination. Palpation of the urethra in cats is of significant clinical interest. It is carried out through the skin of the penis from the level of the ischial arch to the head of the penis, often revealing urethral uroliths or the location of other obstacles to the outflow of urine. Having exposed the head of the penis, they examine the condition of the mucous membrane preputial sac, heads and urethra, often find hyperemic mucous membrane of the urethral opening, urethral plugs of various compositions. In some patients, the urethral plug is extremely firmly “soldered” to the mucous membrane. In cats with severe dehydration, dry necrosis of part of the glans penis may occur. Light massage urethra is performed to obtain urethral contents. Sometimes massage can relieve urethral obstruction. Examination of the urethra: palpation, probing and catheterization make it possible to determine the absence or presence of urethral obstruction and parietal stones. It should be noted that the more proximally the obstruction is located, the less organic matrix it contains, the more difficult and traumatic the procedure for eliminating the obstruction will be.

Special research methods:

· Ultrasound examination (ultrasound) - provides information about the thickness of the walls of the bladder; about the presence of sediment, stones, neoplasms; about the condition of the kidneys. For ultrasound of the urinary tract of cats, high-frequency sensors of 5-7.5 MHz are used, which provide the most reliable image of the internal organs. To ensure full contact of the sensor with the patient's skin, the hair from the area being examined should be shaved. The bladder is scanned in the transverse and longitudinal planes, changing the position of the patient’s body, that is, a polypositional study is used.

· X-ray examination is of secondary importance in the diagnosis of urolithiasis in cats. Stones in the bladder and urethra in cats are usually small and correspond in density to soft tissues. However, it is not advisable to completely abandon radiography, since in addition to a survey image, it is possible to perform a contrast radiograph, including double contrast, urethrocystography and emergency urography, which allows not only to diagnose “urolithiasis”, but also to carry out differential diagnosis.

Laboratory research methods:

· Biochemical examination of urine using diagnostic strips - simple and sufficient effective method express diagnostics, with which you can determine the following urine parameters within 1-1.5 minutes: pH, specific gravity, amount of protein, ketone content, bile pigment content, microhematuria, microhemoglabinuria. The method has a significant drawback - in case of severe gross hematuria, the readings are significantly distorted and do not provide diagnostic value.

· Examination of urine sediment is carried out by microscopy under low and medium magnification. To obtain sediment, freshly obtained urine is centrifuged at 1000-1500 rpm for 5-7 minutes. The excess liquid is drained, the sediment is placed on a glass slide and covered with a coverslip. Microscopy determines the type of crystals, the number of red and white blood cells in the field of view, the epithelium of various parts of the urinary system, and cylinders. Significant gross hematuria is an obstacle to obtaining a “readable” urine sediment. In such cases, to approximately determine the type of crystals, it is reasonable to conduct microscopy of urethral plugs and stones. The results of microscopy of urine sediment and urethral contents almost always coincide.

5. Treatment and prevention

Treatment is aimed at eliminating pain, increasing salt solubility, loosening stones, and preventing further formation of urinary stones. You can alleviate the animal's condition with the help of antispasmodics (baralgin, spazgan), treatment of identified infections with antibiotics (cefa-kure, enrofloxacin, albipen LA), sulfonamides (urosulfan, sulf-120), the drug "Cat Erwin" (for obstruction of the urinary tract, it can be administered directly into the bladder, after pumping out the contents of the latter), as well as with the help of a special diet that prevents oversaturation with calcium and phosphorus salts. To stimulate the smooth muscles of the bladder, gamavit or catazol are recommended, to eliminate urethral plugs - catheterization and lavage of the urethra with the drug "Cat Erwin" (16 ml per dose), hot baths (40ºC) when immersing the cat up to half the body, anti-inflammatory therapy - dexafort .

Cannot be used on cats medical supplies containing glycerin and essential oils - urolesan, cystenal, pinobin, phytolysin, as this can lead to fatal outcome. You can use Avisan, Cyston, but the dosage of these drugs is designed for humans, so it is necessary to take into account not only the weight of the cat, but also its sensitivity to the plants included in the medicine.

1) Manual massage:

Manual massage (often used for cats with sand plugs) or catheterization with a small polyurethane catheter (for example, a special Jackson catheter for cats or a medical subclavian catheter with a diameter of 0.6 - 0.8 mm).

Despite the fact that catheterization is often used to displace or break up uroliths in cats and some breeds of dogs, this method of treatment is the most dangerous for the following reasons:

* it injures tissues, which leads to fibrosis and scarring with subsequent narrowing of the urethra;

* introduces infection into the urinary tract.

2) Retrograde urethral lavage.

Retrograde urethral lavage followed by dissolution (struvite, urate and cystine) or cystotomy (calcium oxalates, other calcium- and silica-containing uroliths) is the only treatment for urethral urolithiasis.

Method of retrograde washing out of urethral stones. The animal is given general anesthesia or strong sedatives. Then the following steps are performed:

* Empty the bladder by cystocentesis (puncture of the bladder through the abdominal wall).

* Through the rectum, fingers compress the urethra opposite the pubis, below the urolith (an assistant is needed for this).

* A sterile catheter is inserted into the distal urethra.

* Secure the penile part of the urethra around the catheter.

* A sterile saline solution is injected into the catheter through a syringe.

* When the intraluminal pressure reaches the desired point, the assistant removes his fingers and releases the urethra.

* Under the pressure of the saline solution, the urolith returns back to the bladder.

*You can repeat the procedure several times.

After retrograde lavage, recurrence of obstruction is very rare. This method, as a rule, is not used in cats; in males, this low-traumatic method is often recommended for use.

3) Urethrostomy.

Urethrostomy is used in males when manipulation or retrograde lavage has not been successful. A urethrostomy creates a permanent opening in the urethra. This method is used for recurrent obstructions of the penile urethra in cats and sometimes in males. Although this is the only method of treating animals with permanent urethral obstruction, it must be used with caution, because according to some data, in 17% of cases, urethrostomy in cats leads to postoperative urinary tract infection. In 10% of cats, urethrostomy and dietary changes also result in postoperative infection, while none of the cats treated with diet develop a urinary tract infection.

4) Dissolution.

Struvite, urate and cystine stones can be dissolved. This is the only method for removing stones in animals with non-life-threatening urolithiasis. Dissolution is used for kidney or bladder stones. If a urinary tract infection is present, antibiotics are prescribed as part of treatment based on the results of urine culture and sensitivity testing. Treatment details are discussed below.

Struvites (magnesium ammonium phosphate, tripel phosphates). To dissolve struvite stones, it is enough to strictly adhere to special veterinary diets.

These foods contribute to the acidification of urine, causing the dissolution of struvite. In addition, the increased sodium content in these diets stimulates diuresis (urination), which helps flush the bladder and speed up the elimination of accumulated salts. For urolithiasis not complicated by bacterial infections, treatment with special diets brings positive results already 4-5 days after the start of treatment. It should be noted that contacting a veterinarian as early as possible and making an early diagnosis of urolithiasis promotes a speedy recovery of the animal and minimizes possible relapses of the disease. The owner's compliance with the animal's feeding regime is of great importance.

Quality control of treatment is carried out by laboratory tests of urine and x-ray diagnosis of the presence of stones in the bladder. If there are no stones in the urine and in the photographs, the treatment is considered effective and the owner’s task in the future is mandatory research urine at least once every six months. Optimal time control testing - 3 months.

Laboratory assessment of urine pH, as well as the presence and analysis of urine sediment, determination of the type and quantity of urinary crystals.

5) Treatment of insoluble uroliths.

Calcium oxalates.

Calcium oxalate uroliths are more common in certain breeds of dogs (Yorkshire terriers and miniature schnauzers), and in recent years they have become noticeably more common, especially in cats.

Unfortunately, this type of crystals is completely insoluble, and treatment of this type of urolithiasis is carried out exclusively surgically, removing stones from the bladder. Sometimes 3-4 operations per year are required if the intensity of oxalate formation is very high.

To prevent relapses, it is necessary to reduce the concentration of calcium and oxalates in the urine. Prevention is possible with special diets.

Calcium phosphates.

Calcium phosphate crystalluria manifests itself in various forms: both amorphous (calcium phosphates) and calcium hydrogen phosphates (brushite). These minerals are often present in mixed uroliths along with struvite, urate, or calcium oxalate. Most calcium phosphate crystals (with the exception of brushite) are sensitive to urine pH and form in alkaline urine.

A medical protocol for dissolving these uroliths has not yet been developed, so surgical removal and prevention of hypercalciuria (as in the case of calcium oxalate urolithiasis), but not urine alkalinization, are recommended.

6) Pulsed magnetic field.

Also in practice, a method is used to treat urolithiasis using a pulsed magnetic field, which not only promotes the dissolution of uroliths, but also has an anti-inflammatory and local analgesic effect. Relief occurs in all but the most advanced cases.

7) Homeopathic treatment.

Monitoring the condition of the mucous membrane of the bladder and urethra in cats with urolithiasis is of great importance.

For this purpose, long-term therapy is prescribed using the drugs Berberis-Homaccord and Mucosa Compositum. Medicines can be given with drinking water 2-3 times a week.

For acute inflammation and pain, traumeel is prescribed subcutaneously 2-3 times a day or in the form of drops every 15-30 minutes. Traumeel is also prescribed after surgery (cysto- or urethrotomy).

If urolithiasis develops against the background of chronic pyelonephritis, then the main treatment is best carried out using the drugs Cantharis Compositum and Berberis Homaccord.

8) Herbal medicine.

Prescribed for chronic disease. Decoctions and infusions of urological preparations have an antiseptic and anti-inflammatory effect and contain compounds that play the role of a protective colloid that prevents the agglomeration of microurolith crystals. The use of phytoelite preparations “Healthy Kidneys” and “Cat Erwin” is recommended. From herbs: decoction of bearberry leaves ( bear ears), infusion of half-palm (erva woolly), parsley rhizomes, knotweed, watercress, etc.

9) Diet therapy.

Currently, feeds are more effective in preventing struvite uroliths, thus the percentage of oxalate uroliths has inevitably increased.

Over-acidification of some cat foods or use of acidifying diets in conjunction with urine acidifiers results in bone demineralization, releasing calcium to provide a buffer.

The increase in cases of oxalate urolithiasis in cats contributed to the development of a new diet, Hill's Prescription Diet Feline x/d, which was created specifically to prevent the formation of calcium oxalate crystals and uroliths and prevent relapses of calcium oxalate urolithiasis. Carefully selected and strictly controlled calcium levels slow down crystal formation. Reduced vitamin content D helps avoid excessive absorption of calcium from the intestine. The increased content of potassium citrate, which can form soluble salts with calcium, contributes to the partial destruction of oxalates, and soluble fiber promotes the binding of calcium in the intestine.

Both struvite and oxalate are most common in overweight, indoor cats with low water intake—the former two factors impair urinary frequency and lead to urinary retention, and the latter factor increases the concentration of minerals in the urine. However, while struvite is more common in young animals (under 5 years), the risk of developing oxalate uroliths is greater in older cats (over 7 years).

Although there are general principles for preventing both types of KSD, recommendations regarding certain nutrients vary significantly. For optimal control of a specific type of urolith, the most appropriate level of each individual nutrient must be strictly controlled. Therefore, there is no diet that is suitable for controlling both types of stones.

The presence of a urinary tract infection with urease-producing bacteria will worsen the development of struvite uroliths. But infection rarely acts as the primary cause of urolithiasis in cats, more often as a secondary or accompanying microflora.

The basic principles of nutrition to prevent urolithiasis are a number of rules:

· Maintain adequate water intake to ensure adequate urine output. Increasing your water intake will increase the volume of urine produced and dissolve the substance that promotes crystal formation. The volume of urine is usually greater in cats consuming a canned diet. Also, if the feed is well digestible, this reduces the amount of dry matter in fecal matter, which requires less water. Thus, water loss through feces is reduced, allowing water to be excreted in urine.

· Avoidance overconsumption those minerals that are components of urolith, thereby reducing their concentration in the urine.

Calcium and oxalate in the intestinal lumen form an insoluble complex that is not absorbed (just as they form an insoluble complex in the bladder). Dietary reduction of just one of these may mean that the other is free to be absorbed and will then be excreted in the urine (where it can bind with oxalate or calcium, which is released from body tissues to form calcium oxalate). It is recommended that calcium and oxalate restriction occur over a long period of time and together. There should not be a large reduction in calcium intake, and its absorption may be reduced by binding to soluble fiber.

Prevention.

Prevention consists primarily of controlling the acidity of urine. Depending on the age of the animal, the types of stones vary, and quite significantly. Thus, in young cats (up to 5 years old) phosphates are most often detected. Acidification of urine prevents their occurrence. In mature cats (6-9 years), the likelihood of phosphate stones (struvite) decreases, but the risk of oxalate stones increases, especially if the urine is too acidic. In order to limit their formation, it is recommended to take measures to reduce the acidity of urine. But in older cats (more than 10 years old), you should be most wary of the formation of oxalate crystals: neutral urine with the addition of potassium citrate limits the danger of their formation. Allopurinol (xanthine oxidase inhibitor) is used to prevent and dissolve urate stones. Cranberry juice is indicated to reduce urine pH and prevent the formation of uroliths. An excellent preventive remedy is the herbal medicine “Cat Erwin”. To restore the body after surgery, the microelement preparation Gamovit-plus is indicated.

Conclusion

chronic urolithiasis in cat

Currently, urolithiasis is very common, the incidence is widespread. Both domestic and wild animals are at risk of developing urolithiasis; therefore, housing and feeding conditions do not play a major role in the occurrence of of this disease.

At the moment the disease is difficult to treat full treatment and the risk of relapse is high. Therefore, the ICD is an extensive field for studying and developing new modern methods treatment.

It should be noted that feeding specialized feeds can reduce the risk of developing urolithiasis, since such food has a balanced composition suitable for the characteristics of the body a separate type animals.

Literature

1. E.M. Kozlov Urolithiasis in cats. N.: MAG TM, 2002. - 52 p.

2. Ed. A.F. Kuznetsova Handbook of Veterinary Medicine - St. Petersburg: Lan Publishing House, 2004. - 912 p.

3. S.V. Starchenkov Diseases of small animals: diagnosis, treatment, prevention. Series “Textbooks for universities. Special literature". - St. Petersburg: Publishing House "Lan", 1999. - 512 p.

4. S.S. Lipnitsky, V.F. Litvinov, V.V. Shimko, A.I. Gantimurov Handbook of diseases of domestic and exotic animals - 3rd ed., revised. and additional - Rostov n/d: ed. “Phoenix”, 2002. - 448 p.

5. A. Sanin, A. Lipin, E. Zinchenko Veterinary reference book of traditional and unconventional methods treatment of dogs. - 3rd ed., revised and supplemented. - M.: ZAO Tsentrpoligraf, 2007. - 595 p.

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Predisposition to disease

To date, it has been established that possible predisposing factors for the appearance of insoluble compounds in urine are: genetic predisposition, animal diet, lifestyle (immobility, obesity), infectious agents, systemic diseases. It has also now been established that insufficient water intake into the cat’s body and an increased urine pH value contribute to the formation of uroliths and the occurrence of urolithiasis. It should be noted that in cats the diameter of the urethral lumen is more than three times smaller than in cats. This causes more frequent clinical manifestation urolithiasis.

Persian and domestic (long-haired and short-haired) cats are most susceptible to the disease. In castrated animals, MBC has been registered in 60% of cases, of which 52% are cats. In non-castrated cats, MBD was observed in 36% of cases of the total number of cases. Among cats - sterilized and unsterilized - the frequency of occurrence is approximately the same. Animals aged 1 to 7 years are most susceptible to the disease (72%). 70% of animals with MBC were overweight. Most often, MBC was observed from January to May (44%) and from September to December (56%). Of all types of uroliths, struvites accounted for 70%. In 24% of animals with MBD that did not use dietary feed as prophylaxis, the disease was recurrent.

Types of main stones formed in cats

Uroliths are polycrystalline formations consisting of minerals. Urethral plugs, which are found in cats, consist of an organic matrix with the addition of minerals. Uroliths in cats vary in chemical composition.

These include:

Struvite - tripelphosphates (magnesium, ammonium, phosphate). Struvites make up 80% of uroliths. Struvite-type urolithiasis occurs in cats aged 1 to 6 years. In cats over 10 years of age, this type of disease is associated with a urinary tract infection whose urine pH is alkaline. It has been noted that struvite is more common in obese cats.

Calcium oxalates - crystal-forming agents - calcium and oxalic acid. Oxalate-type urolithiasis occurs mainly in cats over 7 years of age. Typically, the formation of uroliths of this type is associated with an increase in the level of calcium in the urine (hypercalciuria), the pH of the urine is acidic;

Ammonium urate/uric acid (rarely observed).

Almost all uroliths are localized in the lower parts of the urinary tract, but can also occur in the bladder.

Development of urolithiasis

Struvite or oxalates, when precipitated, form crystals in the form of sand and stones. Passing through the urethra with urine, the crystals injure it, thereby causing pain, inflammation and bleeding. There is an increase in urination, which becomes painful, very often there are traces of blood in the urine or the urine turns cherry color. Next, small stones or several grains of sand get stuck in the urethra, creating a plug there, thereby making the outflow of urine from the bladder very difficult, the cat urinates drop by drop, and often the urine stops flowing completely.

More urine accumulates in the bladder than comes out; accordingly, the bladder overflows, which in turn affects general condition cat or cat. The animal becomes inactive, stops eating and drinking, and constantly tries to urinate. The kidneys continuously continue to secrete urine, and it does not matter whether the animal drinks or not, urine continuously enters the bladder, thereby stretching it to a size comparable to a tennis ball (normally, the bladder is no larger than walnut). Then the animal's condition rapidly deteriorates. Due to overstretching of the bladder, blood vessels in the walls burst, blood pours into the lumen of the bladder, urine enters circulatory system body, thereby causing intoxication.

Then vomiting, trembling, and convulsions appear - these symptoms indicate severe poisoning by substances that make up the urine. External manifestation The disease depends on the shape, size and location of the stones. The disease may not manifest itself externally if the stones do not clog the lumens of the urethral canal and do not have sharp edges that would cause mechanical damage to the mucous membrane. Sometimes, when carrying out visual diagnostic methods, large stones were found in animals, more than two cm in diameter. The formation time of such a stone is at least one and a half years. However, during this period, no complaints or signs of illness were observed. Suspicions of urolithiasis appear only when there is difficulty urinating, in which the animal strains, often takes an appropriate position, and urine is released in a very weak stream, often with blood, at times interrupted or completely stopped. Urine often contains fine sand.

A full bladder indicates urinary retention, a life-threatening condition that requires immediate veterinary attention. Irregular urine discharge leads to chronic cystitis - inflammation of the bladder, urethritis - inflammation of the urethra and increasing self-poisoning of the body - urine, in the absence of an outlet, begins to be absorbed into the blood. Being a toxic and chemically aggressive waste product, urine corrodes the walls of the bladder. The urine takes on the color of cherry juice due to the presence of a large amount of blood in it.

There are 4 degrees of urolithiasis:

Grade 1 – subclinical urolithiasis. There may be no symptoms associated with the presence of crystals in the urinary tract.
Grade 2 – mild symptoms of urolithiasis. Increased frequency of urination, slight staining of urine with blood, increased time and discomfort when urinating. Increased licking of the genitals.
Grade 3 – severe symptoms of urolithiasis. Cats almost never leave their litter box. Obvious blood in the urine. Severe pain when urinating. On palpation, the bladder is greatly distended. General depression.
Grade 4 – life-threatening symptoms of urolithiasis. Anuria, dehydration, vomiting, convulsions, coma. Stage 4 symptoms are more common in males than in females due to anatomical structure urethra.

Diagnostics

Diagnosis of urolithiasis in cats and cats is based on clinical picture, analysis of the collected anamnesis and study of salt sediment in urine. Additional information about the location, shape, size and number of stones can be obtained using x-ray examination and ultrasound examination(ultrasound). Urinary stones consist of a framework formed by protein or other organic substances, and crystals of various salts located around it. There are several methods for determining the composition of urinary stones: crystallographic examination, polarization microscopy, X-ray diffraction and spectral analyzes, as well as electron microscopy. The most accessible and simplest diagnostic method today is the method of chemical analysis of stones.

Treatment of urolithiasis

Conservative treatment is aimed at eliminating pain and inflammatory process, to prevent relapses and complications of the disease. Drug treatment is aimed at eliminating stagnation of urine and restoring patency of the urinary tract.

Obstruction can occur due to spasm of smooth muscles due to irritation of the mucous membrane by the stone. In these cases, antispasmodics and sedatives(baralgin, atropine, platiphylline, spasmolitin). The primary treatment measure for urolithiasis is to ensure adequate urine outflow and restore patency of the urethra. To do this, bladder catheterization is performed under general anesthesia. The impossibility of catheterization is an indication for surgical intervention.

The second stage is aimed at maintaining the body without the formation of large amounts of sand and stones. This is achieved by using preparations to dissolve sand and stones.

After restoring the flow of urine during the first few days, it is necessary infusion therapy(dropper) in order to restore water-electrolyte balance and relieve intoxication. Anti-inflammatory and antibacterial therapy is also carried out (up to two weeks). Stabilization of urine pH from 5.5 to 6.0. Increased fluid intake - urine density 1.015 g/cm3. Avoid thirst.

Surgical treatment of urolithiasis is indicated in the case of prolonged strangulation of a calculus, accompanied by signs of stagnation of urine, the presence of a calculus that is unable to pass on its own, complicated by pain, macro- and microhematuria; state of severe intoxication; Availability concomitant infection, as indicated by a rise in body temperature to 40 C. Contraindication to surgical treatment Urolithiasis is a disease of the cardiovascular system, respiratory and liver failure, and cerebrovascular accident.

The operation is called “perineal urethrostomy,” during which the male penis and testes are removed and a new urethral opening is formed.

The operation is performed only to prevent blockage of the urethra; it does not prevent or cure diseases of the lower urinary system. This means that the formation of salts in the urine, inflammation, painful urination may continue. Cats with a urethrostomy are predisposed to infection in the bladder and the development of infections associated with bladder stones.

Diet therapy

On the effectiveness of therapeutic and preventive measures big influence It has balanced diet, taking into account data on the reaction of urine and the nature of the salts in its sediment. The goal of prevention is to prevent the occurrence of the disease, timely identification of the danger of stone formation and its elimination.

Recommended:
Give plenty of fluid to increase daily diuresis (tea, chamomile decoction, mineral water)
Reducing body weight, this is achieved by reducing calorie intake
Ensuring Consistent Operation digestive tract. In case of constipation, use laxatives that do not cause a shift in the balance of electrolytes. Avoiding hypothermia of the animal.

The choice of diet is made depending on the type of stones that caused the disease.

Diet for oxalate stones

The diet prescribed for oxalate stones should limit the intake of oxalic acid, a large amount of which is found in the liver, kidneys and other foods. The consumption of foods rich in calcium (milk, cheese, cottage cheese, etc.) is limited. It is necessary to include in the diet foods with a predominance of alkaline valences, such as beets, cauliflower, legumes, etc. Recommended foods rich in magnesium (rice, peas, boiled meat, cereals and vegetables). Canned therapeutic and prophylactic food for cats Hill’s Feline X/D. Dry and canned medicinal food Eukanuba Oxalate Urinary Formula.

Diet for phosphate stones

Sick animals with phosphaturolithiasis are prescribed a regimen that promotes the oxidation of urine, its transfer from alkaline reaction to sour. If possible, it is necessary to exclude products with a high content of calcium compounds (milk, cheese, cottage cheese, eggs (yolk), curdled milk, etc.). Recommended: boiled beef, veal, egg (white), rice, carrots, oatmeal (in small quantities), liver, cabbage, fish (eel, pike). Canned and dry medicated food for cats Hill’s Feline S/D, to prevent the formation of struvite Hill’s C/D. Dry and canned medicinal food Eukanuba Struvite Urinary Formula.

Assistant veterinarian at the Bona Mente veterinary clinic Marina Kutasina

Types of kidney stones - classification, chemical composition, features of formation and treatment. Urolithiasis in cats

Clinical symptoms of urolithiasis

Diagnosis of urolithiasis

Treatment of urolithiasis

Dissolution

Treatment of insoluble uroliths

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Predisposition to disease

Types of main stones formed in cats

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Diagnostics

Treatment of urolithiasis

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