Chronic kidney disease is one of the most common illnesses of the ageing cat. The kidneys wear out and filter the blood less well. It cannot be cured, but — and this is the essential point — once detected, it can be managed very well: a monitored cat can live long and comfortably.

What is chronic kidney disease?

The kidneys clean the blood, passing waste out into the urine through a multitude of tiny filters (the nephrons). With age, these filters deteriorate little by little. When too few are left, waste builds up in the blood — a little like a slow self-poisoning — and the signs appear. In cats this wear is gradual (chronic); sudden (acute) forms are rarer and often have a different cause.

Which signs should alert you?

  • The cat drinks far more and urinates more (the earliest sign)
  • It loses weight, eats less, and its coat turns dull
  • Vomiting, bad breath, sometimes small ulcers in the mouth
  • Tiredness — it sleeps more, seems ‘miles away’

These signs creep in slowly and often pass for ‘a cat getting old’.

When to seek help quickly — As soon as your cat is visibly drinking more than usual or losing weight, have it examined. A cat that stops eating or drinking altogether, or is very subdued, must be seen without delay.

How is the diagnosis made?

The vet relies on the symptoms, a blood test (markers such as urea, creatinine and SDMA show whether the kidneys are struggling), a urine analysis and the blood pressure; sometimes an ultrasound scan. This work-up also makes it possible to stage the disease and adjust the treatment.

How is it treated?

The kidneys cannot be ‘repaired’, but the disease can be slowed and the cat made comfortable:

  • A specific renal diet (low in phosphorus, with high-quality protein) — the most effective everyday measure.
  • Encouraging hydration (water freely available, wet food, sometimes fluids given under the skin).
  • Medication as needed: for blood pressure, nausea or excess phosphorus.
  • Regular check-ups to fine-tune the treatment.

Mistakes to avoid

  • Taking the increased thirst and the weight loss for simple effects of age: they are often the first signal.
  • Stopping the renal diet as soon as the cat improves: it continues for life.
  • Restricting water because ‘it urinates everywhere’: on the contrary, it needs to drink plenty.
  • Giving a human medicine on your own initiative.

Prevention and screening

Kidney wear cannot really be prevented, but it can be detected early, and that changes everything: from 7–8 years of age, an annual health check (blood test, urine, blood pressure) can pick up the disease before the symptoms and win precious years of comfort.

The key points: an older cat that drinks and urinates more, or is losing weight, should be examined. Chronic kidney disease cannot be cured but can be controlled well — detected early and monitored, it leaves your cat a fine quality of life.