Q. My son just got diagnosed with ringworm. Should I take my cat in to be checked out? (The cat) doesn't seem to have any dry or balding patches. If my cat does have ringworm, what is the best way to treat it?

A. There are several different strains of ringworm — some are everywhere in the environment and some live on our pets. It is definitely possible for your cat to be carrying ringworm and not have any signs. For this reason you should take your cat to your veterinarian to be tested. Typically, the vet will use a toothbrush to comb the entire cat for spores (which are microscopic) and put them on a culture plate. If nothing grows after several weeks it is probably safe to assume that your son got ringworm from another source. If the cat is positive, you will need to treat the cat and the household. While ringworm is not harmful, children can get recurrent infections if it is present in your household. Your vet will prescribe treatment.

Q. I have a 2-year-old black shorthaired cat. Before I got him, he had a very difficult first year. He had been neglected, and then he was hit by a car, breaking his pelvis. A Good Samaritan brought him to my veterinarian, who treated him then gave him to me. He had no hair on his ears, which has grown back and very little on his shins, which has not. I noticed recently that he is licking his hair off his legs, arms and belly.

My veterinarian said he was suffering from "separation anxiety." I am with him most of each day, and when I'm not, I check in several times. Have you heard of this before? And if so, do you have a suggestion as what to do? My vet said there was medication, but her main suggestion was to get him another cat as a companion.

A. Your cat sounds similar to a cat we had in our shelter recently. It can be frustrating trying to determine if there is a medical reason for the over-grooming or if it's psychological. Sometimes it can be hard to tell if the hair is falling out, or being pulled out. Your veterinarian should be able to look at the hairs under a microscope to help make that determination.

It's a little concerning that when your cat found you he had no hair on his ears: since it would be impossible for him to lick there, the hair may have fallen out on its own. Some of the things that can cause hair to fall out (called "alopecia") in a young cat are allergies, ringworm and parasites in the skin. When cats get a little older we start to worry about endocrine problems such as an overactive thyroid, which turned out to be the case with our shelter cat.

Assuming your veterinarian has checked your cat for medical reasons for the over-grooming, it is often helpful to try a special diet for food allergy. I would always recommend good flea control such as Frontline, applied religiously every month. If no other disease can be found, veterinarians are left with a diagnosis of "psychogenic alopecia," meaning the cat may just enjoy the sensation of licking, or does it out of boredom or stress.

In severe cases, antidepressants can be prescribed. I have also spoken with veterinarians who had success using herbal supplements to help calm the cat. Getting another cat might be a good idea if you thought the he was extremely bored during the day.