How can I tell if my cat is sick?

Look for subtle changes: hiding, appetite or thirst changes, litter box changes, reduced grooming, or lethargy. Cats hide illness, so any shift from normal matters.

When is a sick cat an emergency?

Difficulty breathing, a male cat straining to urinate, collapse, or not eating for over 24 hours all need immediate veterinary care.

Signs Your Cat Is Sick (And When to Act)

4 min readReviewed by Dr. Jane Mitchell, DVM

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Cats are experts at hiding illness. Here are the subtle signs that your cat may be unwell and needs attention.

Cats mask illness

As both predator and prey, cats instinctively hide weakness. That means subtle changes are often the only early clue — so knowing your cat's normal behavior is your best diagnostic tool.

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Behavioral signs

Watch for hiding, reduced activity, changes in appetite or thirst, litter box changes, less grooming (or over-grooming), and irritability. Any noticeable shift from normal is worth attention.

Physical signs

Weight loss, vomiting, diarrhea, bad breath, discharge from eyes or nose, difficulty urinating, or labored breathing all signal a problem. Some — like a male cat straining to urinate — are emergencies.

When to see the vet

Cats decline quickly once ill, so don't 'wait and see' for more than a day with concerning signs. Not eating for 24 hours, breathing trouble, or straining to urinate need prompt care. Regular checkups catch problems early.

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Frequently asked

How can I tell if my cat is sick?: Look for subtle changes: hiding, appetite or thirst changes, litter box changes, reduced grooming, or lethargy. Cats hide illness, so any shift from normal matters.
When is a sick cat an emergency?: Difficulty breathing, a male cat straining to urinate, collapse, or not eating for over 24 hours all need immediate veterinary care.