Introducing new cat to other pets

Dear Dr. John,

As a college student with an interest in a career in veterinary medicine, I thought I would ask you a behavioral question before I inform my parents that I will be bringing another pet home this summer. The cat I adopted is a six-year-old neutered male. He is very calm, loves to cuddle, and never tries to run away. I wonder how I should deal with introducing him at home since we have another neutered male cat and a large dog. I am also concerned that our other cat goes outdoors. At school, my new cat is strictly indoors so I do not know if I should allow him to go outdoors with our family cat. If he does want to go outside, would keeping him indoors cause him to get depressed? If he starts to go outside, will he get depressed when he goes back to being strictly indoors when we return to school? — L.O.

Dear L.O.,

Congratulations on adopting an adult cat and thanks for your questions. You have described a complex situation for which there are no clear answers. First, let me address the introduction of the pets. There is no way of anticipating how they all will react towards one another. Typically, I advise keeping a new cat perhaps in one room alone for a day or two and allow them to smell one another’s presence. Then allow for a gradual introduction ensuring adequate safe space if things don’t go well. Hopefully the cats will get along instantly, but a little fur may fly initially, or they may keep at a distance for a while.

You also cannot predict how your new cat will get along with the dog. Will he like the dog or will the dog want to play with the new cat and the cat think of it as aggression? Once a cat goes outdoors, keeping them strictly indoors later can lead to inappropriate voiding. Since you will take him back to school in the fall, I might suggest keeping him indoors this summer. Now all you have to do is tell your parents! Good luck with all of it.

Dr. John de Jong is President of the World Veterinary Association. He owns and operates the Boston Mobile Veterinary Clinic and can be reached at 781-899-9994.