Q. My dog seems depressed to me. Instead of being energetic and playful as usual, he lies in his doghouse and looks bored. When we go on a walk he doesn't seem interested in exploring as he used to. I myself take Prozac, and it has made a world of difference. Could I give some to my dog to see if it will help?

A. Please check with your vet. A pet that changes behavior might have a health problem that should be addressed. Depression in dogs requires professional diagnosis by an expert in animal behavior.

Prozac has been tested and found effective in treating dogs with compulsive behaviors, such as chewing and licking. If your pet is truly depressed, there may be some other tactics your vet can recommend before resorting to an anti-depressant. You should never share your medicines with anyone in your family, including your pet.

Q. In a recent column you mentioned that Prilosec can reduce the absorption of vitamin B-12. I immediately called my pharmacist about this, because four doctors who have prescribed this stomach medicine for me have never said anything about vitamin B-12.

The pharmacist had never heard anything about this. So far as I know, the maker of the drug has not published any warning, either. So I'd be grateful if you would give me more information.

A. Suppressing stomach acid interferes with vitamin B-12 absorption (Marcuard, Annals of Internal Medicine 1994; 120: 211-215).

Dr. Mark Ruscin at the University of Colorado Health Sciences Center recently studied elderly patients on acid-suppressing drugs such as Prilosec or Zantac. Those taking these drugs for a year or longer are at increased risk for vitamin B-12 deficiency. Symptoms may include tingling or numbness of hands or feet, burning tongue, anemia and confusion.

This Q&A; is from the People's Pharmacy, by Joe Graedon, pharmacologist, and Dr. Teresa Graedon, a medical anthropologist. Write to the Graedons in care of The Sun, 501 N. Calvert St., Baltimore, Md. 21278, or e-mail to pharmacindspring.com.

Pub Date: 5/03/98