The kidneys perform several essential functions that play a vital role in your cat's overall health. Here, our Charlotte vets discuss each stage of kidney failure in cats, as well as symptoms and treatment options.
Your Cat's Kidneys
When your cat's kidneys are healthy they work to remove toxins, manage blood pressure, maintain a normal electrolyte balance, regulate hydration and calcium, and produce hormones that stimulate the production of red blood cells.
If your cat is diagnosed with kidney failure - also known as renal failure - the kidneys are no longer functioning efficiently. This can be caused by several factors and conditions, such as infections, tumors, or ingesting something toxic.
The immediate risk of failing kidneys in cats is that they cannot clear the blood of dangerous toxins.
Types of Kidney Failure in Cats
There are two types of kidney failure in cats. Each type differs in causes, treatment options, and prognosis.
Acute Renal Failure
If your cat is suffering from acute kidney failure, it means that its kidneys are suddenly unable to function properly. This type of kidney failure occurs suddenly, within days or weeks. If diagnosed in time, acute renal failure can often be reversed.
It can happen in cats of any age and typically results from poisons, trauma, infection, organ failure, urethral blockages, dehydration, and other causes. Poisons, such as toxic plants, pesticides, cleaning fluids, and human medications, are the most common cause of acute renal failure.
Chronic Kidney Failure
Chronic kidney failure in cats is a gradual condition that typically develops over several months or even years. This type of kidney failure is typically caused by autoimmune diseases, cysts in the kidneys, and genetics.
Chronic kidney failure is a progressive illness that can lead to total kidney failure, where the kidneys gradually stop working as they lose the ability to filter toxins out of the blood.
Signs of Kidney Failure in Cats
When the kidneys aren’t removing waste from your cat's body properly, you may notice that your kitty is drinking larger than usual amounts of water and attempting to urinate more often. Because the toxins build up in the cat's body, they may feel nauseous and stop eating their food. In general, your cat will appear to be lethargic and not very happy.
General symptoms of kidney failure in cats can include:
- Weight loss
- Excess thirst
- Lack of appetite
- Bad breath
- Diarrhea and/or vomiting (may contain blood)
If your cat is suffering from acute kidney failure you may also notice an arched back or stiff-legged gait, symptoms that your cat’s kidneys are causing pain.
Chronic kidney failure gradually progresses over years, and the signs may not be noticeable. By the time you do see symptoms, the disease may already be leading to total kidney failure.
While there is no cure for chronic kidney disease if it’s detected and treated early your cat’s longevity and quality of life can be improved.
Stages of Kidney Failure
There are 4 stages of renal disease according to the International Renal Interest Society (IRIS) at this point in time. Below are what happens during each stage and how your cat would be cared for.
The cat has a large amount of protein in the urine and high blood pressure. At this stage, your pet will need:
- Dental care as needed, with IV fluid support (you can prolong life expectancy by 2-3 years if your cat does not develop periodontal disease)
- Blood and urine testing at least annually
- Consider an abdominal X-ray to look for kidney stones
- Appropriate medication if the pet has high blood pressure and/or protein in the urine
- Fatty acid supplementation (fish oil) to decrease inflammation inside the kidneys
- Calcitriol therapy to replace the active Vitamin D that the kidneys are no longer producing enough of
At this stage, your cat's urine will no longer be concentrated and they will need all items in Stage 1 plus:
- Blood pressure, blood, and urine testing twice yearly
- Supplementary potassium may be necessary
- Start a kidney disease diet
- Medication to decrease blood pressure within the kidneys
Stage 3 will consist of all components of stages 1 and 2 in addition to:
- A probiotic supplement that helps to trap nitrogen waste products in the intestine
- Blood testing every 3-6 months, urine testing at least annually
- Phosphorus binder medication if phosphorus level climb
- Control side effects of uremia if needed (including nausea, vomiting, and GI ulcers), with medication
Cats in stage 4 will require everything from stages 1-3 as well as:
- Blood pressure and blood testing every 3 months, urine testing at least twice a year
- Anemia treatment as required
How Kidney Failure in Cats is Diagnosed & Treated
Your vet will do a comprehensive examination of your cat, including diagnostic tests such as blood and urine tests, X-rays, and possibly an ultrasound. A kidney biopsy might also be required.
If kidney disease is found, treatments could include intravenous fluids to correct dehydration, vitamin injections, supplements, medications, and possibly surgery to remove blockages. When treating kidney failure the goal is to manage the symptoms and slow down the progression of the disease.
You can support your cat’s treatment with a carefully managed diet and plenty of clean fresh water. Your vet will recommend that you gradually transition your cat to a kidney diet that is low in both phosphorus and protein and is enriched with vitamin D and omega-3 fatty acids.
Palliative care is required for cats with end-stage kidney failure. In their final days, this will mean keeping them warm and comfortable, with food, water, and a litter box nearby, as well as lots of loving human companionship.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding people or pets. Always follow your doctor's advice regarding asthma or other allergy symptoms.