Signs my cat has kidney disease: 9 symptoms UK owners miss.

Chronic kidney disease (CKD) affects roughly 1 in 3 UK cats over the age of 10. It is also the most preventably catastrophic condition in feline medicine — caught at stage 1 it is a manageable diet change, caught at stage 4 it is a goodbye conversation. The difference is whether you spotted these signs.

What is kidney disease in cats?

Feline chronic kidney disease is the gradual loss of the kidneys' ability to filter waste from the blood and concentrate urine. It progresses through four IRIS stages. Once kidney tissue is lost it does not regenerate — every month of earlier detection meaningfully extends quality of life.

The 9 earliest signs of cat kidney disease

• Drinking more water than usual — increased thirst (polydipsia) is the single most common early sign of CKD.

• Urinating more, larger volumes, or more dilute (paler) urine — the kidneys lose their ability to concentrate urine first.

• Subtle weight loss over weeks or months — easy to miss; weigh your cat monthly.

• Reduced appetite or fussier eating, particularly with dry food.

• Bad breath with an ammonia or urine-like smell (uraemic breath) — caused by waste building up in the bloodstream.

• Coat looking dull, unkempt or greasy — declining grooming is one of the earliest behavioural signs.

• Mild lethargy or sleeping in different, quieter spots than usual.

• Occasional vomiting unrelated to food or hairballs.

• Constipation — a side effect of dehydration as the kidneys pull less water back into the body.

How is feline kidney disease diagnosed?

UK vets diagnose CKD with a blood panel (creatinine, urea, SDMA) plus a urine specific gravity test. Cost: roughly £80–£140 for a baseline at a typical UK practice. From age 7 onwards, an annual baseline is the cheapest insurance you will ever buy for your cat.

Can you detect cat kidney disease at home?

Not diagnose — but you can absolutely flag it earlier. Persistently dilute urine and shifting pH show up in the litter tray weeks before the symptoms above become obvious. Health-monitoring litters such as Kittydoctor change colour in response to those exact markers, giving you a daily prompt to call the vet while the disease is still manageable.

What does cat kidney disease cost in the UK?

Stage 1–2 caught early: £180–£350 per year (renal diet + 6-monthly bloods). Stage 3 moderate: £1,200–£2,000 per year. Stage 4 end-stage: £2,400–£4,000+ per year plus emergency admissions. The single biggest financial variable is the stage at diagnosis.