What are the early signs that my cat is sick?

Cats evolved to hide weakness, so subtle shifts — eating less, sleeping more, hiding under the bed, or skipping grooming — are often the first clues. Knowing your cat's normal routine is the single best diagnostic tool you have.

Watch these specific areas. Appetite: refusing food, or suddenly begging constantly. Litter box: urinating more or less, straining, blood in the urine, diarrhea, or accidents outside the box. Grooming: a dull, greasy, or matted coat, or over-grooming one bald patch. Body: weight loss, a distended belly, bad breath, drooling, or a new lump. Behavior: hiding, aggression, yowling, reluctance to jump, or walking stiffly. Eyes and nose: discharge, squinting, or a visible third eyelid. Breathing that is fast or open-mouthed at rest is a serious warning in any cat.

Some signs mean an emergency and you should go straight to a clinic: a male cat straining to urinate with no result, open-mouth breathing, collapse, seizures, bleeding, or vomiting a foreign object. For everything else, a good rule is that any change lasting more than 24 to 48 hours deserves a call to your vet. Photograph or write down what you see — how much your cat eats and drinks, and when it last used the litter box — because this information helps your vet enormously and can move a diagnosis forward quickly.