When we think of our quiet, graceful house cats, it's easy to forget they descend from capable predators. Cats are small compared with their larger relatives—the cheetah, leopard, lion, and tiger—and in the wild, a small cat showing signs of age or weakness was itself vulnerable to being preyed upon. Over time this favored cats who concealed illness and injury rather than advertising it. Domestic cats have inherited that tendency, which means they rarely show obvious symptoms until a problem is well established. It also means owners need to watch for the subtler changes in personality and routine that suggest something is wrong.
1. Behavioral Changes
If your normally social, cuddly cat becomes withdrawn and starts hiding, treat it as a red flag. Cats who don't feel well often take themselves somewhere quiet and out of the way. The reverse can happen too—a usually reserved cat may become clingy and demanding of attention when they're unwell.
Aggression is worth mentioning specifically. A cat who suddenly becomes snappy, swipes when touched, or objects to being picked up when they never used to is very often in pain rather than being difficult. Any noticeable change in your cat's behavior is worth an examination.
In older cats, changes such as night-time yowling, disorientation, altered sleep patterns, or house-soiling can point to cognitive changes or an underlying medical condition. Old age is not itself a disease, and behavior changes in a senior cat deserve investigating rather than accepting.
2. Lower Energy Level
As a rule of thumb, a cat whose energy drops suddenly is either unwell or in pain. Senior cats do slow down gradually, but an abrupt change—particularly in a younger cat—usually means they're avoiding activity because moving makes them feel worse. They may sleep more, stop jumping onto furniture or their usual perches, or lose interest in play.
That reluctance to jump is worth paying close attention to. Arthritis is extremely common in cats and badly under-diagnosed, largely because cats don't limp the way dogs do—they simply stop doing the things that hurt. A cat who no longer gets onto the windowsill they used to love, or who now takes the stairs one at a time, is telling you something. There's a good deal we can do about it.
Not every unwell cat slows down, either. Hyperthyroidism often does the opposite, producing a cat who is restless, hyperactive, vocal at night, and ravenously hungry while losing weight.
3. Changes in Their Coat
A cat who feels unwell or uncomfortable often stops grooming properly, and the coat becomes matted, greasy, dull, or flaky. It's one of the more visible early signs, and worth noticing.
Reduced grooming can also be mechanical rather than a matter of feeling low—an arthritic or overweight cat may simply not be able to reach parts of themselves any more, which is why mats often appear along the back and near the tail base first.
Over-grooming points to a different set of problems. A cat licking or chewing one area until it's bald may have fleas, mites, ringworm, or an allergy—or may be grooming at a painful spot, which is a recognized sign of discomfort underneath. Over-grooming can also be stress-related. Either way, bald patches, broken hairs, or irritated skin warrant a look.
4. Change in Appetite or Thirst
A change in eating or drinking is one of the most useful signals your cat gives you. They may eat less or more than usual, drink noticeably more, or stop drinking altogether. Anything that persists beyond about 24 hours is worth a call, and a cat who has eaten nothing for a day needs to be seen—cats who stop eating can develop a serious liver condition called hepatic lipidosis surprisingly quickly.
A change in a cat's appetite or thirst could indicate:
- Dental disease—a cat may become fussy, chew on one side, drop food, or approach the bowl and then walk away
- Hyperthyroidism or diabetes—often a large appetite alongside weight loss, with increased drinking
- Kidney disease—increased thirst and urination, often with a reduced appetite and gradual weight loss
- Liver disease, cancer, or pain anywhere in the body—reduced appetite without an obvious explanation
Increased thirst deserves particular attention, since it's the earliest sign of several of the conditions we see most often in cats. It's easy to miss if your cat drinks from more than one place, so it's worth noting if the bowl is emptying faster than usual, or if your cat starts drinking from taps, glasses, or the toilet.
5. Litter Box Changes
You've cleaned your cat's litter box often enough to know what's normal, which makes it one of the best monitoring tools you have.
Larger or more frequent clumps of urine can point to kidney disease, diabetes, or hyperthyroidism. Very small, hard, dry stools suggest constipation, which is common in cats and can be linked to dehydration, pain, or kidney disease. Straining, blood in the urine, or going outside the box are all worth reporting—and a cat who stops using the box entirely is usually telling you something hurts.
One situation is a genuine emergency. If your cat is going in and out of the box repeatedly, straining, crying out, or producing little or no urine, they may have a urinary blockage. This affects male cats most often, and it can be fatal within a day or two. Don't wait to see whether it settles—call us or your nearest emergency hospital immediately.
6. Weight Change
Weight loss is one of the most reliable early indicators of illness in cats, and one of the easiest to overlook—a cat can lose a significant proportion of their body weight before it's obvious under the coat, particularly a long-haired cat. Run your hands along your cat's sides and spine every so often, and if they feel bonier than they did, let us know. On a ten-pound cat, losing a pound is the equivalent of a person losing fifteen.
Weight gain matters too, both for what it does to joints and because it's a risk factor for diabetes. Weighing your cat at home every month or two, on a baby or kitchen scale, catches changes long before they're visible.
When to Treat It as an Emergency
Most of the changes above warrant a prompt appointment rather than an emergency visit. A few don't. Please contact us or your nearest emergency hospital straight away if your cat is:
- Straining in the litter box and producing little or no urine
- Having difficulty breathing, breathing with an open mouth, or panting
- Collapsed, unable to stand, or dragging a limb
- Crying out repeatedly, or clearly in acute distress
- Vomiting repeatedly, or unable to keep water down
- Known or suspected to have eaten something toxic
When it comes to your cat's health, anything that seems out of character is worth raising with us sooner rather than later. Cats hide discomfort for as long as they can, which means a problem may be well advanced by the time it becomes obvious. Keep a watchful eye, trust your instinct when something feels off, and don't wait—early is nearly always easier to treat, and we'd far rather see a cat who turns out to be fine.
Contact us if you'd like to talk through anything you've noticed, or if your cat is due for a check-up.