Chronic kidney disease is a common problem in older cats. In most patients there is no inciting cause and is a result of aging. Clinical signs begin to appear when the cat has lost about 75% of kidney function. When kidneys fail, they lose the ability to save water and to remove toxins from the body. The clinical signs most commonly seen are weight loss, loss of energy and loss of appetite. Most cats will also drink more water than usual and urinate large amounts. The rate of progression of signs is variable but generally the signs appear gradually over a period of weeks or months.
Diagnosis is based on physical examination and laboratory tests of blood and urine. The results of the physical and laboratory tests are used to plan appropriate therapy. Most patients can be managed at home with a combination of diet, medication and subcutaneous fluid therapy. Very ill patients require hospitalization and rehydration with intravenous fluids. Those who do not respond to intensive fluid therapy have a grave prognosis. Those who respond can then be managed at home.
Therapy is individualized for each patient. It will be adjusted as needed based on the patient’s clinical signs and laboratory values. These parameters will be evaluated every 4-6 months in stable patients and monthly in more severely affected individuals.
Listed below are the most common therapeutic options. Some patients will need all of the medications listed others may begin with dietary measures alone.
- Free access to water and canned diets to encourage water consumption.
- Reduction of stress and avoidance of environmental changes.
- Dietary restriction of protein and phosphorus. Several commercial diets have been developed to meet these needs and are available from the clinic. These types of diets will help control some of the signs of kidney failure. As with any diet change, they should be introduced to your cat gradually over several days. To encourage appetite, feed frequent small meals that have been warmed. Dry food may be fed free choice. If your cat will not eat the prescribed food, feed anything they want. IT IS BETTER TO EAT SOMETHING THAN NOTHING.
- Control of nausea (Many times the loss of appetite is related to this problem.) Most cats will respond to 2.5 mg of famotidine (¼ tablet of Pepcid a/c 10mg) given once daily at bedtime.
- Subcutaneous fluid administration (may be given at home or at the clinic one or more days weekly as needed).
- Phosphate binders (based on blood phosphorous levels).
- Potassium supplements (based on potassium levels).
- Bicarbonate supplementation (based on total CO2 levels).
- Erythropoietin (procrit injections) – Given as needed for anemia.
Cats with chronic kidney disease are more likely to develop high blood pressure and are also more susceptible to urinary tract infections that other cats. Patients will be monitored for these conditions and treated when necessary. Most of these patients are elderly and should be carefully monitored for other problems such as hyperthyroidism, dental disease, heart disease and diabetes.
The prognosis for cats with chronic kidney failure is variable. The disease progresses at different rates in different patients. Some cats live several months and some several years. Treatment can be very rewarding and can improve the quality of your cat’s life. It involves owners and veterinarians working very closely together to provide the best care for each patient.