Q. My friend gave me a cat about two months ago. He is a 2½-year-old spayed male and is typically a very affectionate and playful cat, however, his behavior changed completely once I returned home from a week-long trip. During my absence, I had my neighbor come over twice a day to feed him and keep him company. She said he was affectionate with her and ate all of his food each day with no abnormal behavior.

Since I returned from my trip, I've noticed that he no longer follows me around the house, does not wait for me to get out of the shower, and will not come when I call. Also, he is not eating regularly and appears lethargic and shows no interest in playing. I've been giving him plenty of affection, and I brush him regularly, but he won't return to his normal and playful self.

I knew he was upset when I left, but I had no idea that it would go this far and for so long. How long should I let this behavior continue before becoming much more concerned?

A. It sounds like you are doing all of the right things to appease your little boy.

However, I am concerned there might be an underlying medical condition that may have been exacerbated by the stress of your absence. I cannot tell you the number of times that a pet has seemed perfectly normal when an owner goes on vacation, only to find this same type of behavior upon return. More often then not, there is a medical problem.

Remember that cats, in particular, are good at hiding their diseases. This goes back to their wild ancestors. If they appeared to be ill in the wild, they would lose their territories, not be able to find a mate, and possibly be attacked.

No single problem leaps to mind based on the symptoms that you have mentioned.

Please have your cat thoroughly checked by a veterinarian. Request a physical examination, a complete blood count (CBC), chemistry panel, urinalysis, fecal examination (even if it looks normal), and possibly a FeLV/FIV test. Keep up the good work, and take care of that little guy.