THE MULTI-CAT HOUSEHOLD
When considering bringing more than one cat home, a look into feline social behavior can be helpful. Making an informed and responsible decision is key to the peaceful existence of cats in multi-cat households.
Felines are naturally social within their own family circle, but can happily survive solitarily, as long as basic needs like territory, food, water, shelter, and affection are met. When considering a roommate for your pet, an assessment of her temperament is necessary.
THE ESTABLISHED CAT
If yours is a home with one grown cat, it is likely that she will not welcome a newcomer. If possible, observe her in the presence of other cats. If she hisses, sprays, or displays aggression, another cat in the house is inadvisable. This is not a no-fault predictor as to the certainty of her getting along with the new cat that you choose, but the likelihood is greater. Consideration of like temperaments is also helpful. If your existing pet is easy going, relaxed, and accepting of new situations, the chances of the pairing working is higher. If she is shy and anxious, a playmate is probably not in her best interest. If she is active with a strong personality, she may intimidate another cat.
When considering integration of two cats, it is helpful to know that cats from the same family are most compatible, but otherwise, here are some findings in connection with feline research:
-Â Â Â A grown cat may be more likely to accept a kitten that another grown cat.
-Â Â Â Opposite-sex non-related cats are generally more tolerant of each other than same-sex pairings.
-Â Â Â Of same-sex non-related pairings, the male-male were more successful.
If you decide to introduce a new cat, understand that these animals need to have space within the home to call their own. Dumping the new cat into the established cat’s space is rarely advisable. Supplying a separate space for the new cat and introducing the two in small segments of time while occupying both with food or toys will help them to ease into acceptance of one another. Plenty of food, water, toys, and attention from you need to made available, in separate areas, to both cats, so that they do not feel the need to compete. Play space needs to be divided and spread out so that they each feel that they have ample space to call their own.
If you feel that the integration of the new cat into your home is not progressing successfully – if there is conflict and tension between the two cats – then separate them once again and reintroduce them even more gradually, using the methods outlined above.  You may also consider speaking to your veterinarian about the use of pheromones or drugs.
LITTERMATES IDEAL
Cats will most easily benefit from and accept the companionship of another cat if they are littermates, together since birth. If two littermates are not available, the pairing of two very young kittens (under seven weeks old) from separate litters is often successful. Taking two older kittens in at the same time may work, but the older the unrelated cats, the more likely it is that problems may ensue. Felines are generally intolerant if other felines outside of their natural family unit.
LOSING A SIBLING
When littermates are raised together, and one dies or is taken away, the remaining one can be traumatized. It may stop eating or sleeping, may search for its sibling, or cry out for her for months. Understand that this cat will not accept a new housemate under these circumstances, for she is already downtrodden with anxiety, depression, and weakness from a scant diet. The ramifications of introducing a new cat at this time could be significant, and integrating a new cat into the household may never work well.
Whether you own a solitary cat who is happy to rule over her home in monocracy, or a cat who values the social interaction that only another cat can provide, knowing the difference is key to a peaceful existence for you and your cat(s).

