That kitten you've just found is awfully cute, isn't he? Unfortunately, your existing cat might not think so! A new kitten can be excellent company for your older cat. With a little bit of patience, you can easily help your cats to become fast friends. Below are some steps you can take towards helping your cats become acquainted:
1. Make Sure Everyone is Healthy
You'll want to make sure your older cat is current on her shots and is not currently suffering from an infectious disease. Cats who spend time outside can easily pick up respiratory infections from passing strays. While easily treatable if caught in time, these can be dangerous for kittens. Also, you'll want to make sure your kitten isn't sick. If your older cat senses that he is, she may be more likely to behave aggressively.
2. Use a Dog Training Crate
This may sound unorthodox, but it's a safe way to begin an introduction to the new kitten. A wire training crate is best, as it allows your other cat to see the kitten better. Place the kitten in the crate, and bring your other cat into the room. Allow her to sniff at the kitten through the bars. Be sure to allow both animals to get plenty of praise for their efforts.
3. Allow Supervised Play Time
If your cat and the kitten seem to be adjusting after a few days, try letting both of them out into the room to play. Make sure you stay around so that necessary intervention can be taken if there's a problem. Should it become necessary to break up a fight, use a cup of water or a spray bottle. Cats don't respond well to smacks with newspapers, flyswatters, or other objects, and may become aggressive if physical punishment is used. Until you can trust your cats being alone together, keep the kitten confined to a separate part of the house when you're not there to supervise unless your older cat is outside when you're not home.
Once you're confident that your cat and kitten can play together, let them start exploring the house together. However, if your older cat is allowed out, you should delay allowing the kitten outside until it's older. Ideally, a kitten should be about six months old, have its first rabies shot, and already be neutered before going out. In most cases, the cats will become good friends.