Adding a new member to your cat family is usually more exciting to you than your current cat. Although solitary by nature, most cats eventually learn to accept, or at least tolerate, newcomers. Because they are very territorial, the way you introduce the new cat to your existing cat can mean the difference between success or catastrophe.
The induction process can take as little as 10-12 days in kittens and very young cats and up to 12 weeks in older cats. It all depends on the personality of each cat. Be sure to give your “first” cat a lot of attention. This will help him feel secure that he isn’t competing for your affection.
Confine your new cat to a “safe” space until the induction process is complete. This should be a small room, such as a bathroom or small bedroom that your current cat rarely visits. Equip it with a bed, scratching post, food, water and a litter box.
In the beginning, your first cat may hiss and howl at the cat on the other side of the door. Just ignore him and walk away. Never punish him for vocalizing aggressively, this will only cause trouble between the two cats. Be sure to praise and pet your first cat when it acts quiet around the new cat’s room.
After a few days, take a rag or washcloth and rub it over your new cat while you pet and play with her. Use another rag to do the same with your first cat. At feeding time, place each cat’s scented rag under the other cat’s bowl. This will help them associate the other cat’s smell with something positive—food. Lots of small feedings each day will help them get used to the smell faster. Make sure you renew the scent on the rags every day.
Next, you can feed them in close proximity. Keep your new cat in her “safe” room with the door tightly shut and place each cat’s bowl on their side of the door. Be sure to feed them at the same time. Once both are eating without growling or hissing, you can move on to the next stage of the introduction.
Lock your first cat in a room she likes to go to and make sure she has water, some favorite food and a litter box. Let your new cat explore the house. After a few hours, bring her back to her room and let your first cat out. He will likely hiss and make a fuss if he smells the scent of another cat in HIS territory. Again, be patient and praise him when he’s calm. Repeat this activity at least once a day until both cats are comfortable.
Before giving the cats full access to each other, have them face each other in a safe situation. Use two hard plastic door stops to open the door to the new cat’s room just 2-3 inches. Make sure the door cannot be pushed open any further and that a cat cannot get its head through the opening. The goal is to give them the opportunity to smack each other’s paws and even go nose to nose without the possibility of full body contact. Feed each cat on their respective side of the door. Once they stop hissing or growling at each other, you can try playing with both of them in the same room.