Q. What is the best way to introduce two new kittens into the home? We already have two cats, one is 16 years old and indifferent and the other is 7 years old and was the baby of the family. The new kittens met our resident cats briefly yesterday. Since then the 7-year-old has been on edge, especially after the 15-minute growling session. How long does it normally take for them to get accustomed to each other and what are the signs that let you know it just won't work? 

A. First, remember that cat introductions must be taken very slowly. Often owners must keep the cats completely separated for up to two weeks. Keep food and litter facilities separate as well. During this time, rotate the cats and kittens around to each room of the house so that they get used to the sounds and smell of each other without visual access.

After this initial period, introduce the cats and kittens at feeding time. Feed them in separate cages or carriers at either end of the room. If they eat in each other's presence, allow one cat or kitten at a time out to explore the area while the others remain in the cage. If no hissing, spitting or brawls occur then short periods of supervised time together can get underway.

In addition, I use a feline pheromone diffuser in the room where the animals will interact under supervision, and I spray the behavior modification product in each room and the carriers or cages the cats use. While your cat may never be friendly to the new cats in general, most cats learn to tolerate one another. Remember to go slow. It can take months for proper introductions to successfully conclude.