Chronic Kidney Disease in Cats: Signs, Stages, Diet and Care

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

The kidneys filter waste from the blood, balance fluids and minerals, regulate blood pressure and help make red blood cells. As cats age, kidney function often declines. Chronic kidney disease, or CKD, affects a large share of older cats, but with early detection and good care, many live comfortably for years.

What is CKD?

CKD is a gradual, irreversible loss of kidney function. Because the kidneys have large reserve, signs often do not appear until a significant portion has been damaged. That is why regular screening matters in senior cats. See the senior cat care guide.

Signs to watch for

• Drinking more water
• Urinating more, or larger clumps in the litter box
• Weight loss and muscle wasting
• Reduced appetite
• Vomiting
• Bad breath, sometimes with mouth ulcers
• A dull, unkempt coat
• Lethargy or hiding
• Constipation or dehydration

Sudden changes, such as not urinating, are an emergency. See signs of a urinary blockage in cats and the emergency warning signs guide.

Causes and risks

In many cats the cause is not found. Risks include age, dental disease, high blood pressure, past kidney infections, inherited conditions such as polycystic kidney disease in Persian-type breeds, and toxins. Lilies are especially dangerous and cause acute kidney failure. See lilies and cats. Human painkillers can also injure the kidneys.

Diagnosis

Your vet will use:

• Blood tests for creatinine, SDMA and urea
• Urinalysis, including urine concentration and protein
• Blood pressure measurement
• Ultrasound or X-rays, if needed
• Tests for other conditions, such as hyperthyroidism, which can hide kidney disease

The International Renal Interest Society (IRIS) stages CKD from 1 to 4, based on blood values, and sub-stages by protein in the urine and blood pressure. Staging guides treatment.

Treatment and management

There is no cure, but treatment can slow progression and improve comfort.

Kidney diet. Veterinary renal diets restrict phosphorus and provide controlled protein. They have been shown to extend life and reduce crises. Many cats need a gradual transition. Ask your vet.

Hydration. Encourage water with fountains, several bowls and wet food. Some cats need fluids under the skin at home, which your vet can teach you to give.

Blood pressure control. High blood pressure damages kidneys and eyes, and medication helps.

Protein loss. Some cats need medication to reduce protein in the urine.

Phosphate binders. Added to food in later stages.

Anti-nausea and appetite stimulants. To keep cats eating.

Anemia treatment. Advanced CKD may require specific medication.

Potassium and other supplements. If blood tests show deficiencies.

Home care

• Offer fresh water in many places.
• Warm food slightly to increase appeal.
• Monitor weight and appetite weekly.
• Keep litter boxes easy to reach. See how often to clean a litter box.
• Record drinking and urination.
• Give medications consistently. See how to give a cat a pill.
• Avoid stress and keep routines steady.

Prognosis

Survival varies by stage and by how well the cat responds. Cats diagnosed at an early stage may live for years, while those with advanced disease may have months. Regular rechecks, typically every few months, allow adjustments. Quality of life should always guide decisions.

Costs

CKD care includes tests, diets, medication and fluids. Ask your vet about a budget and options. See cat vet visit costs, and use the US vet directory to find a clinic.

Prevention

You cannot prevent all CKD, but you can reduce risk:

• Provide regular dental care. See cat dental disease.
• Keep lilies and toxins out of the home.
• Avoid unnecessary medications, and never give human painkillers.
• Encourage water intake.
• Monitor weight.
• Have blood and urine tests regularly after age seven.

Helping a cat eat

Appetite often declines with CKD, so it helps to be flexible. Offer small, frequent meals, warm the food to body temperature and try different textures and flavors within the diet your vet recommends. Switch to a renal diet slowly, mixing it into the old food over a couple of weeks, because pushing a sudden change can lead to refusal. If your cat will not eat the prescribed food, do not let it go hungry. Tell your vet, who may offer other renal diets, appetite stimulants or anti-nausea medicine.

Quality of life

Keep track of good days and bad days, and note whether your cat still grooms, plays, greets you and uses the litter box. These signs help you and your vet judge how treatment is working, and they guide hard decisions later on.

When to call the vet

Call if your cat stops eating, vomits repeatedly, is lethargic, seems weak, has pale gums, urinates abnormally or shows sudden changes. Early action can prevent a crisis.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.