Introducing Your New Cat/Kitten to Your Current Cat

Most species of cats, including the domestic cat, do not normally live in social groups. Although cats can form close attachments to other animals, they are basically solitary.

Cats are very territorial and do not develop the same type of social hierarchies or "pecking orders" as do dogs.  Cats who live in the same house may never become the best of friends, but can usually learn to at least tolerate each other with a minimum of conflict. You will need to take some time to introduce your cat to other family pets in order to prevent fearful, aggressive and behavioral problems from developing.

1. Confine the new cat to one medium sized room with its litterbox, food, water, and a bed. Feed the present cats and the newcomer near either side of the door to this room. Don't put the food so close to the door that the cats are too upset by each other to eat. This will help to start things out on the right foot by associating something enjoyable (eating) with each other's presence. Gradually move the dishes closer to the door until the cats can eat calmly on each side of the door. Next, prop open the door just enough to allow the cats to see each other, and repeat the whole process.
2. Switch sleeping blankets between the new cat and resident cats so they have a chance to become accustomed to each other's scent. Also put the scented blankets underneath the food dishes.
3. Once the new cat is using its litterbox and eating regularly while confined, let it have free time in the house while confining the other cats. This switch provides another way for the cats to have experience with each other's scent without a face to fact meeting, and also allows the newcomer to become familiar with its new surroundings without being frightened by other animals.
4. Avoid any interactions between the cats that result in either fearful or aggressive behavior. If these responses are allowed to become a habit, they can be difficult to change. It's better to introduce the animals to each other so gradually that neither cat becomes afraid or aggressive. You can expect mild forms of these behaviors, but don't give them the opportunity to intensify. If either cat becomes fearful or aggressive, separate them and continue the introduce process in a series of gradual steps, as outlined above.

Precautions: You'll need to add another litterbox, and probably clean all the boxes morefrequently. Make sure that none of the cats is being "ambushed" by another while trying to use the box. Try to keep the resident cat's schedule as close as possible to what it was before the newcomer's appearance.

Cats can make a lot of noise, pull each other's hair, and roll around quite dramatically without either cat being injured. If small spats do occur between the cats, you should not attempt to intervene directly to separate the cats. Instead, make a very loud noise, or throw a pillow at or a glass of water on the cats in order to separate them. Give them both a chance to calm down before re-introducing them to each other. Be sure each cat has a safe hiding place.

Successful introductions require time and patience. Don't expect things to be perfect overnight!

Written by Suzanne Hetts, Ph.D., Certified Applied Animal Behaviorist, Denver Dumb Friends League (Humane Society of Denver)