Buzzards Bay Veterinary Associates - Feline Chronic Renal Failure

BBVA Buzzards Bay Veterinary Associates

230 Main Street * Buzzards Bay, MA 02532 * Tel: 508-759-2521 * Fax: 508-759-6782

Feline Chronic Renal Failure

What is feline chronic renal failure?

Feline chronic renal failure is a gradual decline of kidney function and is generally a disease of older cats. Usually this decline is caused by degeneration of the functional units of the kidney from chronic interstitial nephritis, but other factors can contribute such as high blood pressure, bacterial infection and dehydration. The kidneys become inefficient at their job of filtering out toxins without loosing too much water. Urine becomes dilute while toxin levels build in the blood. The other job of the kidneys is to make the hormone erythropoietin which stimulates the release of new red blood cells from the bone marrow. Without enough of this hormone a cat will become anemic.

What are the signs of CRF?

Increased thirst is usually the first sign that is seen by owners. This usually occurs along with increased volume of urine in the litter pan. As the disease progresses weight loss, lethargy, decreased appetite, vomiting and constipation can all be seen.

How is CRF diagnosed?

Sometimes very early CRF is discovered on routine senior blood work before clinical signs begin. A veterinarian may suspect the disease based on physical exam findings. Blood work and urinalysis are needed to confirm the disease. Often the urine is cultured to rule out bacterial infection of the kidneys. Blood pressure is measured as high blood pressure can contribute to the disease and the disease can cause high blood pressure. Sometimes abdominal radiographs and ultrasound are recommended to rule out stones, cancer and other conditions that can affect the kidneys and urinary tract.

How is CRF treated?

If the disease is first discovered when it is severe often hospitalization with IV fluids is needed. Electrolyte and metabolic imbalances are corrected and nutritional support is given. IV antibiotics are sometimes needed. Despite this aggressive treatment some cats do not get much better. This is an indication that nearly the entire kidney is destroyed and the disease is in the end stages. If a patient responds well to this therapy then they can be sent home and the owner is taught how to care for their cat.

Therapy at home is tailored to the individual cat’s needs.

Usually a prescription kidney diet (such as Hill’s k/d) is prescribed. These diets are helpful because they contain less protein (which causes the generation of toxins), less phosphorus (which is removed by the kidney), more potassium (which is lost by the kidneys) and a healthy balance of nutrients and minerals for cats with kidney disease.

Most cats with CRF can benefit from an antacid for their stomach. Kidney toxins cause increased acid production by the stomach which can lead to vomiting, loss of appetite and ulcers. Usually Pepcid AC is recommended because it can be given once daily and is very safe. It is available over the counter in most drug stores and grocery stores. Your veterinarian can tell you how much to give your kitty.

All cats with CRF can benefit from essential fatty acid supplementation. These fats decrease inflammation, act as antioxidants and actually help the kidneys get a little more blood circulation. A common veterinary essential fatty acid supplement is called Dermcaps. This oil can be added to food daily or administered by dropper into the mouth.

All cats with CRF can also benefit from water-soluble vitamin supplementation, especially B vitamins. Liquid and paste formulations exist.

Many cats with CRF will need potassium supplementation. There are liquid, pill, powder and gel forms of potassium available. Your veterinarian can help you decide which is right for your cat.

All cats with CRF benefit from additional fluids. Though your cat may seem to be drinking a lot already it usually is not enough to fully compensate for the losses. Eating canned food as part of the diet provides moisture and some cats will tolerate additional water being mixed into the food. Some cats will drink chicken broth, watered-down juice from a can of tuna, clam juice or beef broth. It is important to make sure that these do not contain spices such as garlic or onion. At some point in the course of the disease subcutaneous (SQ) fluids are usually needed. Owners can be taught how to do this. It involves using a needle to administer a bolus of the same type of fluids as used for IVs under the skin on the back. This lump of fluid may move around but over several hours is absorbed by the cat. This procedure takes about five minutes twice a week to every day. It is always an option to start SQ fluids early in course of CRF. Often it can slow the course of the disease.

Blood pressure medication, if needed, comes in pill form. Commonly benazepril or amlodipine are used for cats with CRF.

Some cats will eventually develop a high phosphorus level. It is very important to control this as a high phosphorus level can cause mineralization of soft tissues. Aluminum hydroxide, which is sold as a human antacid, binds phosphorus in the intestines and prevents it from entering the body. One common brand name of this product is Amphojel which is sold over the counter in drug stores as a liquid.

If a cat becomes anemic from CRF an erythropoietin hormone (EPO) supplement may be prescribed along with an oral iron supplement. This hormone is given as a series of injections 2-3 times a week until the anemia has resolved. Most cats respond well to this treatment but on occasion the hormone does not work. Unfortunately the only EPO supplements available are exact copies of the human hormone. Cats make a slightly different version of the hormone and some cats are not fooled by the human supplement.

Appropriate antibiotics will be prescribed if needed. Generally infections of the kidney are slow to resolve. The course of antibiotics may be many weeks to many months long.

What can I expect from treatment?

The goal of treatment of CRF is to preserve as much of the remaining functional kidney as possible while keeping the patient comfortable and happy. There is no cure for CRF but with therapy cats can sometimes live for several years after diagnosis. Frequent monitoring is needed to determine if and when changes need to be made to the treatment regime. There is no way to predict if the disease will progress slowly or quickly. Your veterinarian may want to check blood work every month or more right after diagnosis. If the disease progression seems to be slow and the cat is doing well then rechecks are gradually spaced out. The most important objective of treatment is to provide a good quality of life to the pet.

The following is what we recommend for your cat:

Diet:

Supplements:

Fluids:

Blood pressure control:

Phosphorus control:

Antibiotics:

Antacid:

Anemia treatment:

Follow-up exam and/or blood work:

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