Ask the Expert: Current Cat Dethroned by Newcomer

Your Pet Question:

I have a two-year-old male cat and recently (6 weeks ago) we took in an older (6-ish) female cat. Both are fixed. They are not getting along: he is chasing her into corners whenever he sees her, she just sits and growls. One of them has peed in a few random areas in the house (I think it’s the male). Is this likely to sort itself out, or should I just let him have his castle back and look at finding a new home for her?

Jennifer McMorran, Montreal, Quebec

The Expert Says:

It could go either way. He may come to accept her or they may not ever get along or they could still live in the same space peacefully yet never enjoy each other’s company. Slow introduction is usually the best. It’s also important to recognize a cat’s need of vertical space (like leopards in trees) so ensure there are ‘escape’ levels in areas of confinement or bottlenecks like hallways. This could be a bench or play structure which allows one to jump out of the way while the other goes by. It’s best to find out which cat is urinating outside the litter box and have it examined by a veterinarian as stress can worsen some urinary problems that need specific treatment. If there are no medical problems, your veterinarian can recommend products to help eliminate the urine-based marking of territory.

Dr. Kent Morley is the head veterinarian and owner of Properties Animal Clinic, Calgary, Alberta.