Chronic kidney disease (CKD) is one of the most common health problems in older cats. It develops slowly, often with no obvious signs at first, which is why knowing the early clues and having regular checks matters.
How common is it?
The Cornell Feline Health Center describes CKD as the persistent loss of kidney function over time and says it affects up to 40% of cats over the age of 10 and 80% of cats over the age of 15. Age is the only known risk factor. Some breeds carry inherited kidney problems too, such as the cysts seen in Persians (see our Persian lifespan guide).
Early signs
In the early stages there may be no signs at all. The first clue is often:
- Drinking more than usual
- Larger or more frequent urination, with bigger clumps in the litter box
This happens because failing kidneys lose the ability to concentrate urine. If you notice it, mention it to your vet, even if your cat seems otherwise well.
Later signs
- Low energy and poor appetite
- Weight loss and a dull, unkempt coat
- Vomiting or bad breath
- Pale gums, which can point to anaemia
- Sudden vision changes or other signs linked to high blood pressure
About 60% of cats with CKD develop high blood pressure, which is why vets check blood pressure as well.
How vets test for it
- Bloodwork: measures waste products such as BUN, creatinine and SDMA. SDMA rises earlier. According to Cornell, it can be detected when about 40% of kidney function is lost, while creatinine generally rises only after about 75% is lost.
- Urine tests: show how well the kidneys concentrate urine and whether protein is leaking.
- Blood pressure and imaging: blood pressure checks, and sometimes an ultrasound or X-rays.
Vets use a staging system from the International Renal Interest Society (IRIS) to guide treatment.
Treatment and care
There is no cure, so the goals are to slow the disease and keep your cat comfortable. Your vet may suggest:
- A kidney-friendly diet: therapeutic foods with limited protein, phosphorus and sodium. Cornell notes one study found cats on prescription kidney diets lived two to three times longer than cats on standard food. Switch gradually, because a cat that stops eating is a bigger risk than the wrong food.
- More water: wet food, several water bowls or a fountain, and sometimes fluids given under the skin at home.
- Blood pressure and other treatment: medication for high blood pressure, protein loss or anaemia when needed.
Wet food adds water to the diet, which vets often favour for cats with kidney problems. See wet vs dry cat food and the senior cat diet guide, and ask your vet before changing food.
What is the outlook?
It varies a lot with the stage at diagnosis and how well the cat responds. Cornell notes that early diagnosis is linked to better outcomes, and that cats diagnosed at IRIS stage 2 survive a mean of two to three years in many studies, while those first diagnosed at stage 4 on average survive less than six months. Many cats with early kidney disease live comfortably for years with the right care.
What you can do now
- Take your senior cat for checks at least twice a year. See senior cat health.
- Ask about bloodwork and a urine test once your cat is 7 to 10 years old, so you have a baseline.
- Keep fresh water in several spots and consider adding wet food.
- Track weight monthly. See healthy cat weight.
Read about the stages of a cat's life or how long cats live.
Frequently asked questions
What is the first sign of kidney disease in cats?
Often it is drinking and urinating more than usual. Many cats show no signs at all until the disease is advanced, so regular blood and urine tests are valuable.
Can a cat recover from kidney disease?
Chronic kidney disease cannot be cured, but it can often be managed for months or years with diet, hydration and monitoring.
At what age do cats get kidney disease?
It becomes much more common with age. Cornell reports up to 40% of cats over 10 and 80% of cats over 15 are affected.
Should I change my cat's food if it has kidney disease?
Only with your vet's advice. A therapeutic kidney diet is often recommended, but the change should be gradual and your cat must keep eating.
This article is general information, not veterinary advice. If you think your cat has kidney disease, see a vet.