Chronic kidney disease
Also called Kidney failure, CKD, renal disease
A slow, permanent loss of kidney function that is common in older dogs and cats. It often causes no signs until a lot of kidney tissue is gone, so regular blood and urine checks find it earlier.
Cause and spread
- Cause
- A long process that destroys kidney tissue; many different diseases can lead to it. It becomes more common after 5 to 6 years of age.
- How it spreads
- It is not infectious.
Signs to watch for
- Increased thirst and urination, often the first sign
- Poor appetite, vomiting and weight loss
- Dull coat and bad breath
- Weakness and lethargy
- Signs usually appear only after about three-quarters of kidney function is lost
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
Blood tests for creatinine and urea (BUN) show kidney function, and a rising creatinine over time can give an early warning even when it is still in the normal range. Phosphorus and a urine test (concentration and protein) complete the picture, and a blood count may show anaemia.
- Usually the first testKidney Function Test (KFT) - BasicCreatinine and urea (BUN): the first check of kidney function.
- Usually the first testUrinalysis (Complete)Shows how well the kidneys concentrate urine, and finds protein, blood and infection.
- Usually the first testSenior Pet Check (panel)Blood count, liver, kidney, thyroid and urine tests for older pets.
- Supports the diagnosisKidney Function Test (KFT) - AdvancedAdds phosphorus for a fuller picture.
- Supports the diagnosisUrine Protein:Creatinine Ratio (UPC)Shows whether the kidneys are losing protein.
- Supports the diagnosisComplete Blood Count (CBC)May show anaemia from kidney disease.
- Follow-up and monitoringCreatinineFollowed over time to monitor kidney function.
Prevention and control
- Have older pets checked regularly with blood and urine tests, and watch changes in drinking and urination
- Do not give human medicines to pets
- Keep fresh water always available
- Follow your veterinarian's diet and treatment plan
Where this information comes from
- Renal Dysfunction in Dogs and Cats · Merck Veterinary Manual
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.