7 Signs Your Cat Is Sick

From weight changes to strange new habits, this article clues you in to several important warning signs of illness in your cat.

A cat screaming at night could be a sign of illness. By: GalgenTX
Yowling at night (especially in older cats) could be a sign of illness. Photo: GalgenTX

Cats are more sensible creatures than dogs. A cat’s definition of contentment is to find a comfortable place to sleep, rather than chase around after a ball or go for a 5-mile walk.

But this laid-back lifestyle can make it tricky to tell when they’re not well. So to help, here are 7 signs to clue you in that your cat is sick.

1. Change of Habits

Of all the signs, this is perhaps the most important. Over the years, you learn what’s normal for your pet. Cats are creatures of habit and if their routine suddenly changes, this is significant.

  • A familiar reason many clients bring in an older cat for a checkup is that their pet starts to wake them at night crying and meowing like they are possessed. Of course, there could be a behavioral reason for this (such as another cat intruding in the garden), but in older cats increased activity levels or change of sleeping patterns are commonly due to an excess of thyroid hormone (which acts as a stimulant).
  • Another change to be alert for is increased appetite. If your cat starts wolfing down food when previously they were a dainty eater, this is likely to be significant (those thyroid glands again).

2. Mouth Breathing

Dogs get excited — they pant. Dogs are happy — they pant. Dogs run around — they pant.

Not cats.

Panting, or specifically “mouth breathing,” is not normal for cats. Yes, there are the odd exceptions, such as a young cat chasing after a wing-on-a-string for 10 minutes or the stressed cat at the vet clinic, but a relaxed cat chilling in the security of her own home should not pant.

Mouth-breathing in cats is a hint that either their circulation (heart) or respiratory system (lungs) is struggling to cope. Any cat who regularly pants at home should see a veterinarian urgently.

3. Not Grooming

Cats take pride in their appearance, and their behavior is hard-wired to keeping clean. If your cat’s coat becomes dull, unkempt or starry, then he may have stopped grooming. This can be because his mouth is sore or he lacks the energy to keep himself tidy.

Either way, it’s unusual and merits a trip to the vet.

4. Poor Appetite

A change in eating habits for the worse is a significant red flag that all is not right. From the fever associated with a cat bite abscess to kidney disease, there are many reasons for appetite to dip.

The golden rule is that if the cat’s appetite has not returned after 24 hours, seek professional help.

5. Sleeping More

This is a tricky one, because most cats are expert nappers. But there’s something about the quality of a sick cat’s sleep that should put you on alert. Perhaps the cat doesn’t get up to greet you or sleeps through a meal. Cats have habits when it comes to sleep and if they break those rules, something’s up.

By: monkeywing
If your cat won’t even wake up for food, something may be wrong. Photo: monkeywing

6. Thirst

Feline kidneys are designed to conserve water, which is why cats fed moist food rarely drink. A cat on dry kibble drinks more than a cat on canned food, but again, it’s the change you should be alert for.

If you find yourself filling the water bowl more often or the cat litter is soiled more regularly, chances are your cat is drinking more. There are any number of reasons why this happens, including diabetes, kidney disease and infection. Spotting the problem early and seeking help makes a positive difference to the outcome.

7. Weight Loss

The cat who loses weight is burning more calories than she’s eating. It might be that her appetite has dwindled because of sore teeth or feeling nauseous — or, in the case of our hyperthyroid cats, they are eating well but burning calories like there’s no tomorrow. Either way, a cat losing weight is a significant sign and should not be ignored.


Don’t panic if you spot one or more of the signs above. There is a chance the problem is minor (perhaps worms or a mild infection), and if it’s more serious, early treatment helps extend life.

One thing’s for sure: Spotting a problem allows you to seek veterinary help sooner and get your cat back to full health so he can eat, groom and nap just like he always did.


This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Dec. 17, 2018.