Kidney problems are among the most common health issues of older cats, and in general terms they develop slowly rather than arriving as a crisis. The kidneys gradually become less able to concentrate urine and clear waste, so the signs build over weeks and months: a little more drinking, a little less weight, a little less sparkle. Because each change is small, owners often notice them only in hindsight, which is why deliberate observation in a senior cat pays off so well.
Thirst and urine that creep upward
The earliest pattern is usually water. An older cat may visit the bowl more often, drink for longer, or start drinking from places she previously ignored, such as a dripping tap or a water glass. At the other end, the litter tray holds bigger, wetter clumps, and trays need changing more often because the urine is more dilute and more plentiful. Some cats begin missing the tray or urinating in new spots simply because the volume and urgency have increased. These signs overlap with diabetes and thyroid trouble, so they identify a cat who needs blood and urine testing rather than naming the condition themselves. Tracking roughly how fast a measured bowl empties, week to week, converts a vague feeling of drinking more into a trend a vet can interpret.
Weight, appetite and coat in a senior cat
Weight loss in kidney trouble is typically gradual and muscular: the spine and hips feel more prominent, and the cat looks narrower through the back even if the belly seems unchanged. Appetite often becomes inconsistent rather than vanishing all at once, with good days and picky days, a sniff and a walk away, or enthusiasm that fades after a few mouthfuls. Nausea can sit behind that pickiness, and occasional vomiting of food or froth may appear. The coat commonly loses condition, becoming dull, dry or slightly unkempt as grooming drops and the body runs less efficiently. Breath may develop a stronger, sharper smell. Any one of these can have other causes in an old cat, but together with rising thirst they form the classic senior pattern vets ask about first.
Energy, behaviour and the value of senior screening
Energy changes are subtle: longer and deeper sleep, less interest in greeting visitors, fewer trips upstairs, or a cat who quietly withdraws to one room. Some older cats become more clingy rather than withdrawn, so change itself, in either direction, is the signal. This is exactly why routine senior screening matters even when a cat seems broadly well. Blood and urine tests at regular check-ups can reveal kidney changes before the outward signs become obvious, and earlier knowledge gives more room to support appetite, hydration and comfort over time. If your cat is in the senior years and has not had recent blood work, the combination of any thirst increase and any weight drift is a good prompt to book that check rather than wait for the next routine date.
When an older cat with these signs needs prompt care
Book a vet visit soon if thirst and urination have clearly increased, weight is falling, or appetite has become unreliable. Seek help the same day if an older cat stops eating entirely, vomits repeatedly, seems very weak or wobbly, or has breath that smells unusually strong alongside marked lethargy, because a cat who was compensating can tip into feeling seriously unwell. Bring your water and weight observations, a list of current foods, and any recent test results you hold. Storing those senior weight entries and previous blood results in your KinsLe Pet Passport means the vet compares today's findings against a documented history, not a best guess.