You've decided to add a brand new kitten to your household. Congratulations! However, you also have an older cat, and want to make sure that the two get along before bringing the new kitten home. This can be a bit of challenge considering that cats are territorial in general, and sleepy older cats might not want a playful energetic kitten bopping around their home.
So how do you introduce a new kitten to your adult cat without a cat fight breaking out? Here are a few things you should do to introduce your home and your cat to a new kitten, and vice versa.
Consider both cats' personalities
Introducing an older cat to a newer cat is important for keeping your household from falling apart, but can prove difficult. Cats, although capable of forming a friendship with their own species, do not need companionship and are happy to be the sole cat in the house. If your cat is territorial (even without another cat), take extra care to make sure there is no lack of cat necessities (food and water, toys, litter space, resting areas) so your cat won't be inclined to compete with your new kitten. If you have an older cat who is less friendly, try to find a more laid-back kitten, as the two are more likely to be compatible.
Make sure both cats are healthy
Be sure to take both cats to the vet before introducing them to each other. Your older cat should be as healthy as possible before meeting your kitten and should be up to date on vaccinations, as kittens can carry some diseases if they not yet old enough for all their shots. With senior cats, you should take special care to consider any health issues, as they will make your older cat less likely to acclimate to a young, exuberant kitten in the house. Take into account your older cat's needs and your kitten's personality as you plan to introduce the two. They may never be best friends, but they might be able to coexist if you take the right steps.
Prepare your home ahead of time
Before you bring the new kitten into your home, try to take time to prepare your home. Place new items for the kitten (like bowls, litter boxes and toys) around the house prior to the kitten's arrival. That way, your older cat can get used to the environmental changes little by little.
Create a calm environment by using pheromones or calming sprays in your house to sooth your older cat weeks prior to bringing home a new kitten. These can be administered using diffusion or wipes found in your local pet store. American Humane also recommends "trading scents" between the two cats. If possible, bring items with the scent of the new kitten into the house, and bring an item from your home for the kitten in order for them to adjust to the smell (and help them smell more like the house). Some experts recommend swapping out bedding between the two cats so the kitten and older cat can be comfortable with one another's scents prior to meeting.
Finally, if you have the space, it is ideal to make a small room or gated-off area in your home just for your kitten to reside in. This is temporary until the two are fully adjusted to each other, but make sure it contains all the kitten's essentials (like their litter box, food and water bowls and toys).
Go slowly and be patient
The Humane Society of the United states recommends introducing any two pets as gradually as possible. Don't immediately allow the kitten to roam around your house when they arrive. Allow your new kitty and your old kitty the opportunity to smell each other through the kitten's carrying case at first. Then allow the older cat to sniff through the door or gate of the kitten's separate space before allowing the kitten out. The amount of time you do this for will depend on your cats (and your space), but it can range from a day to a few days. This process helps your older cat adjust, in addition to allowing you brand new kitten the opportunity to get used to their new home incrementally.
When you do allow your kitten out, it is best to supervise the two cats for brief amounts of time, to make sure they don't begin fighting. Speak in a calming voice to the two of them, and separate them immediately if you notice either of them becoming angry or aggressive. However, it is best to try to end their interactions on a positive note (so try to remove them from each other's space before they get upset). Continue to swap their bedding as you slowly allow them longer and longer supervised visits.
Each cat is different, so how quickly they become accustomed to one another is all based on the individual cats. Be patient, as this will most likely be a slow process. However, if it seems no progress is being made, and continued or increased aggressive behavior persists, seek advice from your vet or a behavior specialist.