Despite the saying, “Cats are like potato chips, you can’t have just one,” adding a second (or third, or fourth) cat to your home takes careful planning and lots of patience. The resident cat’s temperament and health should also be considered.
Kittens generally appreciate a playmate, and littermates are most likely to get along well.
Adult cats may or may not enjoy having another feline quartered on them. Cats that were socialized with other cats when young are more likely to appreciate a companion. Territorial cats may be most resistant.
Elderly and infirm cats are very unlikely to enjoy a playful young addition to the home.
Slow and steady wins the race
Upon arrival, put the new cat in a private room to settle in. Make sure there is plenty of enrichment in the cat’s new digs. Keep your resident cat away from the door for a few days or until neither cat approaches the door with aggressive posturing or avoids the door and appears fearful. When both cats are relaxed, you may allow them to approach the closed door and sniff one another in the space underneath. If there is no progress, feed them progressively nearer to the door when the other cat is nearby.
The next step is to open the door a crack (one inch). Use a hook or doorstop to prevent the cats from pushing the door open. Monitor for signs of stress or aggression such as hissing or growling or signs of fear. When the cats settle down, you may place a gate (or stacked gates) in front of the door and open it up completely. Make the introductions fun by playing with the cats and feeding them in one another’s company. Keep the exposures brief at first (5 to 10 minutes).
Gradually allow the cats to spend more time together. Supervise the interactions until you are confident that their interactions are without aggression or fear. Make sure to set your home up with an “atmosphere of plenty” in which the important resources are duplicated so the cats can eat, drink, play, rest, and use the litter box without having to be near one another.
Make sure to set your home up with an “atmosphere of plenty” in which the important resources are duplicated.