Quick answer: cat kidney disease (chronic kidney disease, or CKD) is a gradual loss of kidney function, most common in cats over 7. Early signs are drinking and weeing more and losing weight. It can’t be cured, but diet and treatment can help many cats live comfortably for years.
Chronic kidney disease is one of the most common conditions vets diagnose in older cats. The kidneys have a lot of spare capacity, so signs often appear only after significant damage. That’s why regular check-ups and blood tests for older cats matter.
Early symptoms of kidney disease in cats
- Drinking more water and producing more urine
- Weight loss and muscle loss along the back
- Reduced or fussy appetite
- Vomiting
- Bad breath, sometimes with mouth ulcers
- A dull, unkempt coat
The stages of cat kidney disease
Vets use the IRIS staging system, based on blood and urine tests:
| Stage | What it means |
|---|---|
| 1 | Kidney changes but normal blood values; often no signs |
| 2 | Mild loss of function; may drink more |
| 3 | Moderate disease; signs usually obvious |
| 4 | Advanced disease; cats often feel unwell |
Your vet will also check blood pressure and urine protein, as both affect treatment and outlook.
How diet helps
A kidney (renal) diet is one of the most important treatments. These foods typically contain restricted phosphorus, moderate high-quality protein and added omega-3. Studies have shown renal diets can help cats with CKD live longer and feel better. Switch gradually, as some cats are fussy.
Other supportive steps your vet may suggest:
- Phosphate binders mixed into food
- Encouraging drinking with wet food and water fountains
- Medicines for blood pressure, nausea or appetite
Kidney support products
Hill’s PRESCRIPTION DIET k/d Kidney Care Dry Cat Food Salmon
Hill’s PRESCRIPTION DIET k/d Kidney Care Dry Cat Food with Chicken
Browse cat kidney and liver care and prescription cat diets.
What is the life expectancy of a cat with kidney disease?
It varies widely with the stage at diagnosis and response to treatment. Many cats diagnosed early live well for several years.
Can cat kidney disease be reversed?
Chronic kidney disease can’t be reversed, but its progress can often be slowed with diet and treatment.
What is the best food for a cat with kidney disease?
A renal diet chosen with your vet. Wet versions also help with hydration.
This article is general information and not a substitute for advice from your vet.