Feline Renal Disease

Feline renal disease is a condition that affects kidney function in cats. The disease often develops in cats as they age. As kidneys lose nephrons--the units responsible for waste elimination--toxins that are usually filtered out of the cat's body begin to build up and cause harm. The first signs usually associated with feline renal disease are an increase in the cat's fluid intake and an increase in urination.

  1. Kidneys

    • The primary functions of kidneys are to filter toxins out of the body, to regulate electrolytes and urine, and to produce erythropoietin (which helps bone marrow create red blood cells) and rennin (a blood-pressure-regulating enzyme). Feline renal disease can impact all of these functions. The kidneys have strong reverse capabilities, so when the first signs of renal failure appear, it is likely that 60 percent to 75 percent of renal tissue has already deteriorated. Only about 30 percent of renal function is needed for the kidneys to operate normally.

    Symptoms

    • Beyond excessive thirst and urination, later symptoms of feline renal disease may include vomiting, emaciation, loss of appetite and weight, licking lips, constipation, gagging, poor hair coat, nausea, weakness, lethargy, ulcers, halitosis, depression, convulsion and, in the last stages of the disease, coma. It is unlikely all symptoms will be present in affected cats.

    Diagnosis

    • If these symptoms are observed, your cat should be evaluated by a veterinarian. It is likely that blood and urine tests will be conducted. One common type of blood test is for blood urea nitrogen (BUN), a chemical produced in the liver that increases as kidney function fails. High amounts of phosophorus or creatinine in the blood may also indicate renal failure. Urine tests focus on signs of infection, concentration ability (cats affected by feline renal disease are unable to concentrate urine when they become dehydrated) and protein loss. Other methods of kidney evaluation include ultrasound and X-ray. The kidneys of cats with renal failure are often irregularly shaped and undersized.

    Chronic vs. Acute

    • Chronic renal failure is a progressive and irreversible disease. While symptoms may seem to appear out of nowhere, this is because cats can hide the earlier, subtler symptoms of the disease.
      Acute renal failure is an abrupt failure of renal function, and is often associated with a reduction in urine production. It can become fatal extremely quickly, but with the right veterinary treatment kidney function can be restored.

    Treatment

    • Intravenous fluids are often used in the treatment of feline renal disease. For longer periods of therapy, fluids can also be administered under the skin. Lack of potassium has been linked to feline renal disease, so a high-potassium diet could be effective as well.