Whilst introducing an adult cat to a resident cat can be quite easy, often people opt to get a kitten instead in the hope that their resident cat will warm to it more easily. Kittens have no social skills and have not yet reached sexual maturity so they pose less of a ‘perceived’ threat to an adult cat.
Only you will know if your cat will accept a newcomer (be it an adult or kitten) and you need to choose carefully and consider both the age and gender of your resident cat. You can read my post on Choosing a Companion for Your Cat for more on this subject.
Getting a kitten is a big commitment and you are going to be faced with at least a couple of weeks of disruption to your normal schedule in order to effectively introduce the new kitten to your resident cat. Make sure you are prepared for this as if this crucial period isn’t handled carefully, the long-term effects on your home environment and resident cat(s) can be quite negative.
When you bring your new kitten home remember this is a very stressful and scary time for them. They are still very young and are now away from their mum and littermates for the first time. Place your kitten in a safe room and open the lid on the crate or cage you carried them in. Allow them some time in this room to feel safe and explore. You can remain with them if you want to but they will need to spend a couple of days here in isolation so it’s ok to get on with some chores around them.
When I bought my new kitten home, I purchased a Confidence PET Fabric Indoor Foldable Dog Playpen Puppy Guinea Pig Exercise from Amazon. I already had two adult cats so needed a safe place for my new kitten to get comfortable but also a place that didn’t prevent my other two cats going about their normal behaviour.
Once your kitten is confident in his/her new environment, let the cats interact through a closed door, this allows the two cats to smell each other and forms positive associations between the new scent and play. You can also feed your cats on either side of the door to form more positive associations with things they like and the new smell.
Once both cats seem happy with the non-visual contact, wedge the door open and let the cats see each other. Repeat step 2 and give them some food so they associate the newcomer with something good. Don’t worry if there is a bit of uncertainty or hissing and swiping at first. Just give them a little more space and if it’s too much for either cat, go back to the non-visual method. The key here is to build trust between the newcomer and resident cats.
This photo of my new kitten eating next to my four-year-old resident adult male was taken three days after the kitten came home with us. Teddy was a very confident kitten and Herbie accepted him quite quickly as a playmate.
Once the kitten is settled (this may take a few days or even a week) and appears keen to leave his safe room and explore further, allow the kitten time to explore the rest of the house. Keep your resident out of the way, you can let them explore the kitten’s safe room during this time. Let the kitten get comfortable in their new surroundings. Play with your kitten and once it has become relaxed and playful in its new environment you can let your resident cat back in. Make sure to provide an exit for both cats and also a safe hiding place for the kitten in the event he/she feels threatened or it all gets too much.
It’s now time to meet face to face and it’s very common that at this point there is going to be some hissing and possible defensive behaviour such as posturing, puffing or swiping. Kittens possess very few social skills at this stage in their young lives so the most likely outcome is that the kitten will either back off or just look perplexed at your resident cat’s reactions. Don’t worry if either cat retreats or hides, they need to face each other in their own time. Hide and seek is actually a great way for them to interact and get to know each other. Cats are curious so before long one will be looking for the other.
The resident cat may observe the new kitten from a distance at first as they’ll want to assess the new arrival and check there is no threat or danger. If they aren’t keen on getting close or if one of them isn’t keen they’ll make their feelings known. Over time (usually a few days) the cat with become more comfortable with the kitten’s presence. They will tolerate each others presence and aggression will fade. You can begin feeding them closer to each other and games help keep them entertained and distracted from each other. They are also an opportunity for interaction and the chance to make sure the kitten knows who’s boss.
Depending on the personality of both cats you may find they become best of friends. They may share sleeping areas and groom each other. Equally, you may find they simply tolerate each other and stick to their own sleeping areas which is fine. If you followed the above steps carefully and allowed both cats time to adjust to each other’s presence then aggressive behaviour should not be a problem for you.
Enjoy your new kitten and remember to always feed and fuss your resident cat first as this helps to maintain their status as the boss.