Nephritis in cats: what is it, causes of the disease, diagnosis

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“Nepnritis” translated from Greek, nephritis is a severe, infectious-allergic disease that directly affects the kidneys. It can occur acutely, subacutely and chronically, and the area of localization is diffuse and focal. Depending on the stage of the disease, the symptoms and treatment of nephritis in cats vary. The kidneys act as a kind of filter, taking on all the negative consequences of infectious diseases, inflammatory processes and allergic reactions. It is important to understand that this is a dangerous disease that requires the intervention of a qualified specialist.

What is jade?

In fact, the term “nephritis” hides a number of inflammatory kidney pathologies that arise as a result of the influence of various unfavorable factors on the animal’s body. Acute forms of the disease in most cases develop against the background of severe bacterial and viral infections in the cat’s body.

In this case, the kidneys may suffer not only due to the influence of toxic substances produced by pathogenic microflora, but also due to the penetration of viruses and bacteria into the tissues of this paired organ. At the same time, acute nephritis in an animal can occur due to the release of a large amount of toxins into the blood due to severe injuries, burns, allergic reactions, etc.

With persistent pathological processes in the animal's body, chronic nephritis can develop in cats. When the process is advanced, glomerulonephritis is diagnosed, in which inflammation affects the functional glomeruli of the kidneys, causing their death. In addition, purulent damage to the renal pelvis and inflammation of the renal tubules are possible, leading to a violation of the filtration capacity of the organ.

How to make an accurate diagnosis

Unfortunately, the symptoms of nephritis in cats are very similar to the signs of many other diseases of the genitourinary system - cystitis, bladder damage, kidney stones, etc. Therefore, an accurate diagnosis in this case can only be made by a veterinarian.

At the clinic, a cat with suspected nephritis will first undergo laboratory tests of urine and blood. The veterinarian will also most likely prescribe an abdominal ultrasound for the animal. In addition, when diagnosing this disease, procedures such as electrophoresis and x-ray examination of organs can be performed.

If nephritis is suspected, the urine of cats is checked primarily for changes in pH and specific gravity. Also, in this case, doctors can conduct research on the subject of an increased number of leukocytes and red blood cells, as well as a high concentration of salts. If kidney inflammation is suspected, veterinarians usually conduct a blood test, both general and biochemical.

Causes and symptoms of the disease

There are many reasons for the development of inflammatory kidney damage in cats. Most often, such a violation occurs due to the influence of the following unfavorable factors:

helminthic infestations;
acute and chronic infectious diseases;
poor nutrition;
eating poor quality food;
chemical poisoning;
irrational use of drugs;
injuries;
burns;
allergic reactions;
severe dermatological diseases.

In addition, autoimmune processes occurring in the animal’s body can contribute to the appearance of inflammatory kidney damage. There is also the possibility of a hereditary predisposition to developing nephritis. Some cat breeds are more likely to suffer from inflammatory kidney disease than others.

The symptoms of nephritis depend on the degree of neglect of the pathological process. In some cases, cat owners fail to notice that the animal has a problem, because... the inflammatory process is short-term in nature and its manifestations decrease after the cause of the problem is eliminated. However, if the inflammation affects large areas of the kidneys and persists for a long time, the symptoms become extremely severe. Signs of this pathological condition include:

loss of appetite;
decreased mobility;
oppression;
swelling of the base of the ears, eyelids and mucous membranes;
darkening of urine;
gray-green impurities in the urine;
vomit;
strong thirst;
increased blood pressure;
increase in body temperature;
drying of mucous membranes;
unpleasant odor of urine;
dyspnea.

In addition, inflammatory damage to the kidney tissue leads to severe pain in cats. Because of this, palpation of the abdomen, as well as the process of urination, can cause a feeling of anxiety in the animal. The cat may meow pitifully. If the organ is severely damaged, the pet stops going to the toilet.

Publications in the media

Chronic interstitial nephritis (CIN) is a chronic lesion of the tubulointerstitial tissue of the kidneys, caused by the influence of infectious, metabolic, immune, toxic factors, the clinical picture of which is dominated by impaired tubular functions.

Classification • By pathogenesis •• Primary CIN - primarily occurring in the kidney •• Secondary CIN - nephritis is one of the manifestations of a general or systemic disease • By etiology (see below Etiology).

Statistical data. Accurate data are not available due to underdiagnosis. Etiology • Drugs (see Acute interstitial nephritis) • Metabolic disorders: hyperuricemia, hypercalcemia • Immune disorders: SLE, Sjogren's syndrome, chronic active hepatitis, thyroiditis, kidney transplant rejection • Heavy metals: gold, lead, mercury, lithium, etc. • Infections, for example chronic pyelonephritis • Malignant neoplasms: myeloma, light chain disease • Amyloidosis • Kidney dysplasia: polycystic disease, Allport syndrome, etc. • Urinary tract obstruction.

Pathogenesis . Of particular importance in the development of tubulointerstitial inflammation is the predominance of the mechanisms of toxic and metabolic kidney damage over the immune one.

Pathomorphology • Lymphohistiocytic infiltration of the interstitium • Stromal sclerosis • Dystrophy or atrophy of the tubular epithelium • With analgesic nephropathy, the following changes: •• sclerosis of the capillaries of the mucous membrane of the urinary tract •• papillary necrosis •• focal segmental glomerulosclerosis.

Clinical picture • Tubular disorder syndrome • Proximal tubular disorders (complete Fanconi syndrome or partial disorders - proximal tubular acidosis, glycosuria, proteinuria) • Distal tubular disorders (distal acidosis, hyper- or hypokalemia, hyper- or hyponatremia) • Partial tubular dysfunction - depend on the etiological factor • Arterial hypertension (rarely in the early stages, in the later stages and with chronic renal failure - often) • In secondary CIN - symptoms of the underlying disease

Laboratory data • In the blood - anemia, acidosis, increased ESR (more often with immune or infectious genesis) • In the urine - increased volume (polyuria), hyposthenuria, water-electrolyte disturbances, alkaline urine reaction, tubular proteinuria, glycosuria, erythrocyturia, leukocyturia • Hyperuricemia (with gouty nephropathy).

Instrumental data • For all CIN, ultrasound shows a decrease in the size of the kidneys and an increase in the echogenicity (density) of the kidneys • For analgesic nephropathy: •• excretory urography - signs of papillary necrosis (see Renal papillary necrosis) •• CT - calcification of the border of the renal papillae •• cystoscopy - pigmentation of the triangle of the bladder.

CLINICAL AND LABORATORY FEATURES OF SOME CHINA Drug nephropathies • Analgesic nephropathy •• Develops when taking metamizole sodium or combinations of analgesics (paracetamol, phenacetin, acetylsalicylic acid) more than 3 g/day •• More often observed in women over 45 years of age •• Episodes of renal colic in combination with aseptic leukocyturia, gross hematuria •• Microhematuria, moderate proteinuria (massive proteinuria more than 3 g/day - with the development of focal segmental glomerulosclerosis •• Polyuria, hyposthenuria, thirst (100%) •• Renal tubular acidosis (10–25%) •• Reduction in kidney size •• Severe anemia that does not correlate with the degree of chronic renal failure •• Hyperuricemia •• Arterial hypertension is noted in half of the patients •• Acute renal failure (obstruction of the rejected papilla, arterial hypertension, dehydration) •• High risk of developing malignant tumors of the urinary tract •• Analgesic syndrome - combined with kidney damage to other organs: gastrointestinal tract (stomach ulcer, stomatitis), hematopoietic organs (anemia, splenomegaly), cardiovascular system (arterial hypertension, atherosclerosis), neuropsychic sphere (headache, psychosis, personality disorders), reproductive system (infertility , toxicosis of pregnancy), skin (pale yellow pigmentation of the skin).

• Cyclosporine nephropathy •• Develops in a transplanted kidney when using high doses of cyclosporine - 10-15 mg/kg/day •• Interstitial fibrosis •• Arterial hypertension •• Slowly progressive chronic renal failure •• Obliterating angiosclerosis •• Focal segmental glomerulosclerosis with high proteinuria, uncontrolled arterial hypertension and rapidly progressing chronic renal failure.

• Nephropathy caused by taking NSAIDs •• Increased blood pressure •• Edema - primary renal sodium retention due to Pg inhibition •• Acute tubular necrosis with acute renal failure. Toxic nephropathies

• “ Golden” nephropathy (in the treatment of rheumatoid arthritis) •• Glomerulonephritis - membranous, with minimal changes or proliferative •• Tubular dysfunction •• Vasculitis of the renal vessels •• Full restoration of function 11 months after discontinuation of gold treatment.

• Lithium nephropathy •• ADH-unresponsive nephrogenic diabetes insipidus, incomplete distal tubular acidosis and azotemia (rare) •• Nephrotic syndrome. • Cadmium nephropathy •• Impaired functions of the proximal tubules •• Progression to chronic renal failure. • Lead nephropathy •• Decreased GFR, renal blood flow, minimal proteinuria, unchanged urinary sediment, hyperuricemia, low urate clearance, sometimes hypertension, hyperkalemia and acidosis. • Nephropathy with copper administration - rarely observed (Wilson's disease), clinically similar to cadmium nephropathy. • Mercury nephropathy •• Membranous and proliferative glomerulonephritis •• Atrophy of the proximal tubules with the development of Fanconi syndrome •• Progression of chronic renal failure.

Metabolic nephropathies • Urate, or gouty, nephropathy - damage to the tubules by uric acid and urates during alcoholism, treatment of tumors with cytostatics, gout, lead intoxication - there are three types •• CIN •• Urate stones •• Acute uric acid nephropathy (obstruction of the renal tubules by urates with frequent development of acute renal failure). Treatment: diet with the exclusion of purines, allopurinol, forced polyuria, alkalinization of urine • Calcium oxalate nephropathy - damage to the tubules by calcium oxalate crystals during ethylene glycol poisoning, the formation of ileojejunal anastomosis, pyridoxine or thiamine deficiency •• Interstitial nephritis •• Calcium oxalate nephrolithiasis •• Syndrome acute uric acid nephropathy (obstruction of the tubules with crystals with the possible development of acute renal failure).

Other nephropathies that develop secondary to the following diseases • Amyloidosis (see Amyloidosis) • Sarcoidosis (see Sarcoidosis) •• Kidney sizes are usually normal, slight proteinuria •• Hypercalcemia and/or hypercalciuria in sarcoidosis can lead to acute renal failure, nephrocalcinosis or nephrolithiasis • SLE and other systemic connective tissue diseases • For hereditary nephropathy - polycystic disease, Allport syndrome • For urinary tract obstruction (prostate adenoma, urolithiasis, etc.) • For urinary tract infection (chronic pyelonephritis).

Treatment • Cancellation or reduction of the dose of drugs, replacement with an alternative drug • In most cases, a diet that alkalinizes the urine • Sufficient volume of fluid to achieve polyuria • For immune CIN - GC • Correction of water-electrolyte disturbances and ACR • Treatment of arterial hypertension • Treatment of anemia • Treatment of acute renal failure .

Prevention • It must be remembered that in the presence of kidney disease (especially gout, myeloma nephropathy, diabetic glomerulosclerosis) or episodes of acute renal failure in the past, as well as in old age, with heart failure, cirrhosis of the liver, alcoholism and drug addiction, the risk of nephrotoxic effects increases •• Compliance diets •• Achieving forced polyuria with the threat of tubular obstruction with oxalates, urates •• Prohibition of taking analgesics (paracetamol is less toxic) and exclusion of nephrotoxic drugs •• Refusal of X-ray contrast studies in the presence of risk factors for CIN • Reducing doses of cyclosporine to 5 mg/kg/day with monitoring its content in the blood • Early detection and treatment of the underlying disease.

Course and prognosis • Spontaneous restoration of functions or improvement of the course of the disease is possible with rapid withdrawal of the toxic factor, drugs (for example, gold preparations) • CRF is irreversible, more often with analgesic nephropathy. Abbreviation: CIN - chronic interstitial nephritis.

ICD-10. N11 Chronic tubulointerstitial nephritis.

Diagnostics

A veterinarian diagnoses feline nephritis. To clarify the nature of the problem, it is often necessary to exclude a number of other pathologies that may have similar symptoms. Diagnosis of the disease begins with examination of the animal and palpation of the kidney area.

The specialist collects anamnesis to determine the conditions in which the cat lives and what food and water it consumes. To identify the problem and the cause of its occurrence, specific tests and examinations are prescribed, including:

general and biochemical blood and urine tests;
electrophoresis;
Ultrasound of the kidneys;
radiography.

If necessary, additional studies such as MRI and kidney tissue biopsy are prescribed.

How to make an accurate diagnosis

Treatment of nephritis

Acute nephritis in cats is accompanied by severe pain and can cause severe complications, so this pathological condition requires an integrated approach to treatment. Therapy is selected taking into account the reasons that caused the development of the inflammatory process. Throughout the entire period of the disease, the animal needs to be provided with peace and warmth.

In acute cases of illness, the cat should be limited in food for 12 hours. In this case, the pet must have access to warm, settled water. After this, the cat suffering from inflammatory kidney disease is switched to a low protein diet. You should not give your animal fermented milk products, as well as food that contains a lot of salt and hot spices.

Drugs for this disease are selected individually. In acute cases of pathology and severe pain, corticosteroids are often prescribed, incl. Dexamethasone and Prednisolone. If the inflammatory process occurs due to the activity of pathogenic microflora in the cat’s body, broad-spectrum antibiotics are prescribed. Drugs belonging to the group of cephalosporins are often used. To improve kidney function and eliminate edema, diuretics are selected. Often used:

Furosemide.
Temisal.
Parsley infusion.
Bearberry decoction.
Magnesium sulfate, etc.

For constipation, cats suffering from nephritis are given laxatives. You can use Vaseline oil, Lactusan and Duphalac. For diarrhea, medications are prescribed such as:

Vetom 1.1.
Linux.
Hilak-Forte
Verakol, etc.

If pronounced signs of intoxication appear in your pet, you need to start using drugs such as Liarsin and Enterosgel. To eliminate signs of dehydration, the animal is often prescribed Ringer-Locke solution with glucose. In addition, for inflammatory kidney damage, cats are prescribed B vitamins, antiemetics and sedatives. The duration of drug treatment depends on the severity of the existing manifestations of the disease. The dose of medication is selected individually.

Jade in cats: first aid

Providing first aid to a pet excludes the use of medications by the owner, therefore any illiterate use of medications can aggravate the problem.

situation and complicate the course of the disease.
If you observe symptoms indicating nephritis or other diseases affecting the kidneys and genitourinary system, the most important thing you should do is to provide your cat with a diet until the doctor arrives. The diet consists of excluding dry food, salty foods, fried foods, and foods high in chemical additives from the diet.
After diagnosis, if necessary, the doctor prescribes the necessary treatment. In some situations, surgery may be required. Always follow your veterinarian's directions. Our center employs only certified specialists who are able to provide quality assistance!

Nephritis in cats: prevention

The only thing better than any treatment is its absence. To avoid the occurrence of diseases, you need to carry out a variety of preventive measures that will help strengthen the animal’s immunity.

Here are some tips that can help avoid nephritis in cats:

Monitor your cat's blood pressure;

give the necessary physical activity to the body;

avoid hypothermia;

monitor the quality of food;

take vitamin complexes;

visit your veterinarian regularly;

access to a tray with water should always be available;

Monitor your pet's hormonal levels.

Prevention

Considering that the prognosis of nephritis is not always favorable and animals often die due to kidney inflammation or their lives are shortened due to the process becoming chronic, efforts must be made to prevent the occurrence of such a pathology. To reduce the risk of developing such kidney diseases, animals should be given only high-quality feed. When it is not possible to prepare your cat’s food yourself, you need to feed the animal only premium dry food. The pet must have constant access to drinking water.

All cats need physical activity for their health. Low mobility leads to a deterioration in metabolism and the formation of excess fat deposits. You also need to monitor your pet's weight. The animal must be protected from hypothermia. It is necessary to regularly fight fleas and give the cat anthelmintic drugs.

In addition, it is necessary to regularly clean the animal's tray using disinfectants. It is necessary to monitor the cat's health, and if signs of any abnormality appear, you should contact a veterinarian and begin targeted treatment. These measures can reduce the risk of developing inflammatory damage to kidney tissue in cats.

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Therapeutic measures

Let us immediately note that self-treatment is strictly contraindicated, especially for infectious nephritis. It is necessary to conduct research and take tests. An ultrasound examination of the affected kidneys will not hurt. All this is done to determine the exact type of pathology. This determines how to treat a sick animal. It is simply impossible to do all these manipulations at home, so immediately take your pet to a veterinary clinic. However, there are some recommendations for owners, following which you can alleviate the animal’s condition. Firstly, diet. Dry food, as well as salty, smoked, and fried foods should be excluded from the cat's diet. This is what to feed a cat with nephritis.

If the animal has been treated with something, immediately inform the veterinarian, who will decide whether to continue therapy or stop using the drug. The cat needs to be given complete rest and provided with plenty of clean, cool water. If antibiotic therapy is carried out (and this is probably the case!), then water will become especially important.

How long do cats with kidney failure live?

If we are talking about acute renal failure, then with proper treatment, the animal will return to a full life. Although, since the pathology of renal failure is not eliminated, the cat will always require careful care - diet, periodic visits to the veterinarian. If the disease has reached the terminal stage of chronic renal failure, then, unfortunately, treatment will no longer help. It is unknown how long the pet will live at this stage. It depends on his age, the condition of other organs, and care. In the most severe manifestations of the terminal stage, the animal is euthanized, since chronic renal failure is accompanied by excruciating pain.

An animal with chronic renal failure can fade away in a matter of days

Symptoms: how does the disease manifest itself?

Nephritis in a cat has the following symptoms:

As a result of the illness, the pet develops characteristic shortness of breath.

hyperthermia;
frequent and scanty urine mixed with blood or cloudy sediment;
lethargy, loss of interest in life;
lack of appetite;
increased thirst;
frequent shallow breathing or shortness of breath;
swelling of the paws, eyelids, ears;
pain during urination;
cyanosis or yellowness of mucous membranes;
vomit.

What role do the kidneys play in the body?

The kidneys are a paired organ whose task is to filter metabolic products and cleanse the body of toxins. In addition, they maintain water balance, acid levels and electrolyte composition of the blood, perform hormonal functions, and regulate blood pressure.

Each kidney has the shape of a bean, covered on the outside with a dense capsule, and containing contents consisting of kidney tissue. The kidney can be divided into two parts, each of which performs a specific task: the kidney tissue filters blood to form urine; The pyelocaliceal system is responsible for the storage and excretion of urine.

When damaged, kidney tissue does not recover. If the kidneys stop coping with their tasks, the cat develops severe intoxication, disturbances in water, protein, and electrolyte balance, which can lead to the death of the four-legged pet.

As practice shows, kidney disease occurs three times more often in cats than in dogs. It is believed that this is due to their ability, borrowed from their wild ancestors, to make do with a small amount of water. If at the same time a domestic cat eats dry food, then the water balance is disturbed, and this, in turn, causes serious health problems.

The anatomical structure of the genitourinary system is also of great importance: a narrow and long urethra provokes blockage of the urethra and non-excretion of urine, which creates additional stress on the organ, up to its failure.

What symptoms indicate pathology?

Often, glomerulonephritis in cats is asymptomatic for a long time, only sometimes becoming aggravated. That is why the diagnosis is made only after undergoing the required diagnostic measures. The symptoms of this disease are quite varied. The intensity of symptoms is directly related to the age of the cat, general health and type of pathology. If an acute stage is observed, the signs are clearly expressed. The pet's condition is rapidly deteriorating. When it comes to a chronic type of disease, it can last for years, causing serious deterioration in the cat’s general health and the development of various pathologies of internal organs.

If your cat's urine has acquired a dark appearance and has a pungent odor, this may be a symptom of the development of an illness.

The main sign that indicates the development of pathology is the presence of blood, flakes and protein in the urine. The biological fluid becomes dark in color and has a rather pungent and specific aroma. As for other symptoms, the following signs are characteristic of glomerulonephritis in cats:

constant drowsiness;
decreased activity;
loss of appetite;
thirst;
hair loss;
discomfort during urination;
attacks of nausea and vomiting;
pain in the back;
increase in blood pressure;
weight loss.