Companion Cat Kidney Disease: Early Detection and Welfare Management

Chronic kidney disease (CKD) is the most common cause of death in older cats, causing progressive, often painful deterioration. Early detection and evidence-based management can significantly extend quality of life for affected cats.

Key Facts

CKD affects an estimated 30-40% of cats over age 10 and over 80% of cats over age 15
The kidneys have enormous compensatory capacity; clinical signs typically only appear when 75% or more of kidney function has been lost
Early stage CKD is now detectable using the SDMA biomarker test before the traditional creatinine-based tests become abnormal
Key welfare-relevant signs include weight loss, increased thirst and urination, nausea, vomiting, and reduced appetite — all of which impair quality of life
Dietary management with a prescription kidney diet slows disease progression and is among the most evidence-based interventions available
Hypertension is a common complication of feline CKD and causes additional organ damage including retinal detachment and blindness if untreated

Welfare Considerations

CKD in cats causes progressive welfare suffering through the accumulation of uremic toxins, electrolyte imbalances, nausea, and anaemia. Because cats mask illness effectively, owners frequently do not detect CKD until it is advanced — a welfare failure that earlier diagnostic testing can prevent. Annual SDMA screening from age 7 can detect CKD at International Renal Interest Society (IRIS) Stage 1 or 2, when interventions are most effective. The welfare-oriented approach to CKD management prioritises quality of life over quantity: aggressive restriction of a cat's favourite foods in pursuit of marginal disease slowing may reduce wellbeing rather than enhance it. The goal is to maintain adequate nutrition, control nausea and hypertension, and ensure the cat remains interested in life. Subcutaneous fluid administration — taught to owners for home use — is a highly effective welfare intervention that maintains hydration and reduces uremic symptoms in advanced stages.

What You Can Do

Schedule annual blood tests including SDMA kidney function screening from age 7
Begin kidney-supportive dietary transition at IRIS Stage 2 when it produces the greatest benefit
Monitor blood pressure in CKD cats — hypertension causes additional organ damage and requires treatment
Learn to administer subcutaneous fluids at home if recommended by your vet — it dramatically improves quality of life in advanced CKD
Focus on quality of life indicators — appetite, grooming, social interaction — not just laboratory values in CKD management
Discuss euthanasia timing openly with your vet to prevent prolonged suffering in terminal CKD