12 Subtle Signs Your Cat Is Sick (and When to Call the Vet)

Cats are experts at hiding pain and illness. In the wild, showing weakness can make an animal a target, so cats instinctively act normal for as long as they can. By the time a cat looks obviously unwell, a problem may have been developing for a while. Learning the subtle signs helps you catch issues earlier, when they are often easier and less expensive to treat.

Changes in eating and drinking

1. Eating less or skipping meals

A cat that stops eating is always a concern. Cats that go without food for even a few days can develop a serious liver condition called hepatic lipidosis. If your cat has not eaten in 24 hours, call your vet.

2. Drinking much more water

Increased thirst can be a sign of kidney disease, diabetes or hyperthyroidism, all common in middle-aged and older cats. You may notice the water bowl emptying faster or larger clumps in the litter box.

3. Weight loss or gain

Gradual weight changes are easy to miss under fur. Weigh your cat monthly or run your hands along its back and ribs to feel for changes.

Litter box changes

4. Straining or frequent trips

Frequent visits that produce little urine, straining, crying in the box or blood in the urine can signal urinary problems. A male cat straining with little or no urine is a life-threatening emergency because of the risk of a urinary blockage. Go to a vet immediately.

5. Going outside the box

Sudden accidents are often blamed on behavior, but they can be caused by pain, arthritis or illness. Check our litter box guide for setup tips, but see your vet first.

6. Diarrhea, constipation or vomiting

An occasional hairball is common, but frequent vomiting is not normal. Repeated vomiting, diarrhea lasting more than a day or two, or constipation needs a vet check.

Behavior and appearance

7. Hiding more than usual

If a social cat suddenly hides under the bed, it may be feeling unwell or in pain.

8. Less grooming or over-grooming

A greasy, unkempt or matted coat can mean your cat feels too sick or sore to groom. Over-grooming that causes bald patches can point to allergies, skin problems or stress.

9. Changes in activity

Sleeping more, reluctance to jump, or moving stiffly can signal pain, including arthritis, which is very common in senior cats.

10. Bad breath or drooling

Dental disease is extremely common in cats. Bad breath, drooling, pawing at the mouth or dropping food can all point to painful teeth or gums.

11. Changes in vocalization

New or excessive meowing, especially at night in older cats, can be linked to hyperthyroidism, high blood pressure, cognitive changes or pain.

12. Changes in breathing

Cats normally breathe through their nose with very little effort. Open-mouth breathing, panting, coughing or wheezing is not normal for a cat.

Emergency signs: go to a vet now

• Straining to urinate with little or no urine
• Difficulty breathing, open-mouth breathing or blue-tinged gums
• Collapse, seizures or sudden weakness
• Sudden inability to use the back legs, often with crying
• Suspected poisoning, such as contact with lilies, antifreeze or human medications
• Major injuries, such as falls or being hit by a car
• Repeated vomiting or vomiting with lethargy

How to keep your cat healthy

• Schedule annual wellness exams for adult cats and twice-yearly visits for seniors (around age 10 and up).
• Keep vaccines and parasite prevention up to date, as recommended by your vet.
• Keep your cat at a healthy weight with measured meals and daily play.
• Reduce stress with predictable routines and plenty of enrichment.

Frequently asked questions

How can I tell if my cat is in pain?

Look for hiding, squinting, a hunched posture, reluctance to move or jump, reduced appetite and changes in grooming or temper.

Do indoor cats really need vet visits?

Yes. Indoor cats still develop dental disease, kidney problems, diabetes and other conditions that regular exams can catch early.

Is it normal for my cat to throw up hairballs?

Occasional hairballs can happen, but frequent hairballs or vomiting deserve a vet visit. Regular brushing helps reduce hairballs.