Eye spy
Look for bright, clear, evenly focused eyes. Redness, discoloration or discharge, squinting, or the emergence of the third eyelid can signal that your cat has a problem.
Lend an ear
The hairless part of your cat’s ears should be clean and odorless. If your cat is having problems, he may shake his head a lot and scratch his ears. Check for flaking, scabs, foul odor, or discharge. If you see a black, gritty substance inside, he probably has ear mites, a parasite that causes severe itching and is contagious to other cats.
Skin deep
While petting your cat, feel for any lumps, scratches, scabs, swelling, or any other irregularities. Dandruff, oily fur, and missing fur can indicate skin or internal problems. Part the fur to look for fleas; specks that look like black pepper are actually “flea dirt” (flea feces that contain your cat’s blood and turn red when wet).