Kidney Failure in Cats

Kidney failure can either develop slowly due to a chronic disease or occur suddenly due to poisoning or trauma. Both types must be addressed immediately in order to save the cat's life.

The kidneys are responsible for several necessary life functions, which include maintaining proper blood pressure levels, filtering toxins and wastes from the bloodstream, excreting the wastes through urine, contributing to the production of red blood cells, and producing a variety of essential enzymes and hormones. Approximately 30 percent of cats will develop kidney disease during their lifetime; many of these cases will progress to kidney failure. When the kidneys fail to perform properly, the cat's life is at risk.

Depending on the type of kidney failure the cat is experiencing, symptoms can progress slowly or begin suddenly. These symptoms include:

• Increased thirst due to the buildup of toxins and waste in the bloodstream (polydipsia)
• Increased urinary output
• Loss of appetite
• Weight loss
• Bloody or cloudy urine
• Vomiting
• Diarrhea
• Bad breath that smells like ammonia
• Oral ulcers on the tongue and gums
• Dry coat
• Constipation
• Brown-colored tongue
• Weakness
• Lethargy
• Indifference

Types

There are two different types of kidney failure:

• Acute, which develops within days or weeks
• Chronic, which develops slowly over time due to chronic kidney disease

There are several of causes of kidney failure in cats, which vary depending on the type the cat is experiencing. These causes include:

Acute

• Poisons, such as antifreeze, pesticides or cleaning fluids
• Heart failure with low blood pressure that prevents enough blood from flowing to the kidneys
• Trauma from an accident
• Shock from dehydration or rapid blood loss
• Kidney infection
• Urinary tract obstruction

Chronic

• Congenital and hereditary abnormalities
• Fungal infections
• Bacterial infections
• Repeated urinary infections that wear the kidneys down over time
• Kidney cancer
• Medications, such as acetaminophen
• Autoimmune disorders
• Advanced dental disease
• Thyroid problems

The veterinarian will need to know all of the symptoms the cat is experiencing and when the symptoms first began. If a recent poisoning or trauma occurred, the veterinarian will need to be given details about these incidents. The veterinarian will physically examine the cat, listening to its heart and lungs and taking its blood pressure.

A urinalysis and a biochemical profile will be taken. The urinalysis will look for protein in the urine that has leaked through damaged kidneys and will measure the urine specific gravity (USG). Because kidney failure results in the kidneys no longer filtering the wastes from the urine, a cat who has kidney failure will have urine with a gravity that is much like distilled water. The biochemical profile will look for waste products in the blood that the kidneys should have filtered out; high numbers of these products are indicative of kidney failure.

Acute Kidney Failure Treatment

Cats who have acute kidney failure due to trauma or poisoning will often recover once the primary issue that caused the kidney failure is addressed. This may include surgery, medications, fluid therapy or blood transfusions. If the kidneys don't respond after the primary issue is treated, other courses of treatment will need to occur in order to address the kidney failure.

Dialysis

Hemodialysis or dialysis is a procedure in which a machine acts like the kidneys, filtering out the wastes and toxins that build up in the bloodstream. Dialysis can be used to treat cats with chronic kidney disease or to remove a poison from a cat with acute kidney disease. Unfortunately, dialysis is only available at certain veterinary hospitals in the United States and can be extremely costly. 

Kidney Transplant

Kidney transplants in cats require an experienced team of veterinary surgeons, anesthesiologists, and nursing staff. As such, they are only performed in a few veterinary hospitals in the United States. During the kidney transplant, a healthy kidney from a deceased donor cat will be transplanted into the cat with kidney failure. Medications will need to be administered in order to ensure the cat's body doesn't reject the donor kidney.

Cats who recovered from acute kidney failure will need to follow up with the veterinarian to ensure that the kidneys are still functioning properly with repeated testing. There is no cure for chronic kidney failure. Cats who are unable to have dialysis or a transplant have a poor prognosis. Many owners opt to have their cat euthanized as a result. Cats who received a transplant will need to follow up continually with the veterinarian to ensure that the transplanted kidney is still functioning properly. Cats who are receiving dialysis will need to continue with dialysis for the rest of their life or until kidney transplantation is possible.