Any change in your cat’s normal behavior, such as increased lethargy (tiredness), changes in appetite, weight loss, or hiding in the house may be indications that your cat is ill.
Male cats that frequent the litter box but are unable to urinate should be seen by a veterinarian immediately.
If your cat has eaten string, and a portion of the string is still visible, leave the string in place, and see your veterinarian as soon as possible.
If your cat becomes ill outside of normal clinic business hours, call an emergency veterinary clinic for guidance.
Some illnesses require immediate veterinary attention, so when in doubt, call a veterinary professional.

How Can I Tell if My Cat Is Sick?

Any decreases in energy level, appetite, or weight may signal that your cat is not feeling well. If your male cat is squatting to urinate, but no urine appears, call your veterinarian immediately. It is common for the urinary tract in male cats to become blocked. This condition is not only extremely painful; it’s a medical emergency.

It is also common for cats to ingest string, yarn, or dental floss, which can cause problems in the intestinal tract. If you notice a string hanging from your cat’s mouth or anus, do not pull the string out. Leave the string in place and bring your cat to the nearest veterinary clinic.

Other signs that your cat may be ill include:

Bloody urine or accidents outside the litter box
Increased drinking and/or urination
Vomiting
Diarrhea or bloody stools
Constipation
Sneezing or nasal discharge
Runny eyes or holding one eyelid shut
Difficulty breathing
Limping or inability to use hind legs
Unusual lumps, bumps, or swellings
Bad breath or excessive drooling
Hiding or yowling

If you are concerned that your cat may have a fever, you can measure its temperature with a thermometer in the rectum. Normal temperature for a cat is 100.5 to 102.5 degrees Fahrenheit. If your cat’s temperature is above or below this range, contact your veterinarian.

What Should I Do if I Suspect That My Cat Is Sick?

If your cat shows signs of illness, don’t wait—call your veterinarian at once. If it is outside of normal clinic business hours, contact an emergency veterinary clinic. Some illnesses may require immediate veterinary attention, so it’s in your cat’s best interest for you to ask if it needs to be seen right away.

If your cat goes outdoors, you may not always know when he or she has been exposed to toxins or suffered trauma from cars, dogs, or cat fights. Internal injuries may not be immediately apparent, but should be attended to as soon as possible. If you suspect that your cat may have been injured, call your veterinarian.