Q. My 4-year-old spayed female cat has been acting normal; however, her third eyelid has been showing for the past few days. Can this indicate an illness?
A. Protrusion of the third eyelid (or nictitans) in a cat has the common name of haws and is a non-specific finding in many cats. Oddly enough, when veterinarians see that particular clinical sign we often find that these cats have some sort of gastrointestinal disorder. In the old days veterinarians simply assumed it meant that the cat had intestinal parasites. Today, although we test the feces to rule out parasitic problems, we also tend to look for other underlying causes of the problem. This can also be a general sign of dehydration, so be certain that your kitty is drinking. Although this is not an emergency, I would recommend that you take her to your veterinarian as soon as possible to have a full checkup and a fecal analysis.