Symptoms

Early signs of kidney disease in cats

Updated 2026-07-16 · Not a substitute for professional veterinary care

Catch it early

Short answer

Kidney disease is common in older cats and develops slowly. The earliest signs are drinking and urinating more, then gradual weight loss and a reduced appetite. Cats hide it well, so it is often advanced before it looks obvious. Tracking water, weight, and appetite at home, plus routine senior blood tests, catches it early, when diet and care make the biggest difference.

Why kidney disease is so easy to miss

Chronic kidney disease is one of the most common serious conditions in cats over seven, and it comes on gradually over months or years. The kidneys lose function quietly, and cats compensate so well that owners often notice nothing until a lot of function is already gone.

That is the frustrating part and the hopeful part at once: it is easy to miss, but it is also very catchable if you know the early signals and track them.

The earliest signs, in the order they usually appear

Drinking more water. Often the very first sign. The kidneys can no longer concentrate urine, so the cat loses more water and drinks more to keep up.
Urinating more. Bigger or more frequent clumps in the litter box, a natural partner to the extra drinking.
Gradual weight loss. Slow enough to be invisible day to day, which is why a monthly weigh-in matters.
Reduced or picky appetite. Eating less, or going off a favourite food.
A duller coat and lower energy as the disease progresses.

The drinking-more and urinating-more pair is the classic early combination. On its own each is easy to dismiss, which is exactly why noticing both together is so useful.

What to do if you see these signs

Book a vet visit. A simple blood and urine test can confirm kidney values, and often catches the disease long before a cat looks unwell.
Bring your notes. How much the water and weight have changed, and over how long, helps the vet enormously.
Ask about diet. A kidney-support diet is one of the most effective tools, and starting early makes a real difference.

Why tracking at home changes the outcome

Kidney disease rewards early detection more than almost any other feline illness, and its earliest signs are exactly the ones a home log captures well: water, weight, and appetite. Owners who track these notice the drift months before it would be obvious.

Hirra is built for this. A five-second daily check-in and a monthly weigh-in let its on-device early-warning engine flag the rising-thirst and falling-weight pattern and point you to a vet. It never diagnoses kidney disease, that is your vet's job with a blood test, but it helps you get there sooner.

When in doubt, call a vet. This guide is general information for cat owners. It is not veterinary advice, and it is not a substitute for professional veterinary care, diagnosis, or treatment. If your cat is in distress, contact a veterinarian or your nearest emergency clinic straight away.

Notice the quiet changes early

Hirra is a free, private cat-health app. A five-second daily check-in learns your cat's normal and flags the drifts in weight, thirst, appetite, and litter that owners miss, and its free "Is This Safe?" checker looks up foods in seconds. It never diagnoses. It helps you notice, and points you to a vet sooner.

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Common questions

At what age should I start watching for kidney disease?

Risk rises from about seven years, and many vets recommend routine senior blood work once or twice a year from then. Tracking water and weight at home is worth doing at any age, since it costs nothing and catches other problems too.

Is a cat drinking more water always kidney disease?

No. Increased thirst can also point to diabetes or an overactive thyroid, among other things. It is a signal to see a vet for a simple test, not a diagnosis on its own.

Can kidney disease in cats be cured?

Chronic kidney disease cannot be reversed, but it can be managed well for a long time, especially when caught early with diet and care. That is why noticing the first signs matters so much.

Sources

This guide draws on the following veterinary references: