Any advice for incorporating a new kitten into a home with one full-grown cat?

Our family is planning to take in a new kitten. He’s about six months old. We already have a full-grown cat (6 years old) who’s not particularly used to sharing her space with other animals. Any advice on how best to handle this situation?

I just got a new kitten about a month ago, and my older cat is not happy with it especially since the baby seems to think she is Mommy and follows her around.

What I did at the beginning is keep them separate when I was out of the house, put one or the other in the cat’s room (a storage room full of cardboard boxes with food and water an extra litter box) and keep an eye on them and their interactions when I was home.

Now that the kitten is a little older, I let them both have the run of the house even while I’m away, but still use the cat’s room once in awhile to give the older cat a break. Also, don’t fuss too much over the kitten when the older cat can see; I try to distribute my pettings equally.

I don’t think the older cat will ever like the little intruder, but she is getting used to it.

My limited experience would indicate the older cat will ignore the younger one until it gets bigger, then they’ll have a few spats and settle into a pattern of lying around in the same place. YMMV

If the kitten is six months old, it’s probably old enough to be ok introduced exactly the way you’d introduce another adult cat. Keep them separate for a while, slowly feeding or giving treats when the cats are right at the opposite sides of the door between them, then open the door a crack so they can see each other while they’re getting the treat or food but can’t yet interact. Trade materials they like to sleep on (blanket, cat bed, towel, etc) from one cat’s area to the other’s so they get used to each others’ scents. Brush them both with the same brush, etc, to blend the scents.

Then once they seem ok to be near each other without interacting (while being given food or treats), give them brief interactions. Separate them after a short while or at the first sign of fighting for the initial period. Separate them after 30 minutes or so even if they are getting along great.

Add a third litterbox if you don’t already have three, when you let the kitten out into the shared space. (Cats sharing space means you need litterboxes equal to number of cats plus one.) Play with both cats for at least fifteen minutes a day, extra play time with the kitten if he starts pestering your adult cat when she doesn’t want to play.

Use “feliway” spray or scent for the first week(s) they are out and about together. This helps establish a peaceful cohabitation for cats by pheromone influence. Spray in places where the people and cats tend to hang out together.

Make sure there are escape routes at any location where one cat ambushes the other. You can use wall shelves or other climbing apparatus to help with this, or just move furniture around, etc. Otherwise you might get spraying at the ambush site if one cat is able to frequently corner the other and attack when the other one just wants to get from point a to point b.

The adult cat being the female and the kitten being the male, you’re likely to have a problem period when the kitten first gets larger than the older cat. You might need to get the Feliway out again and start fixing ambush points again even when you thought everything was going great. This may happen anytime between 9 months and 2 years old, depending on the cats’ sizes and growth patterns which vary a lot, but the male cat will probably end up bigger than the female.

Some cats really hate it when a formerly littler cat gets to be a bigger cat than they are. Some cats that used to be littler take too much advantage/revenge when they get to be bigger. So it will be a period where you have to be careful to give them enough play, time outs separated from each other, and possibly new escape routes will need to be created.

Wife and I took in a female ~6 month old kitten last January while already having a 10.5 year old female. Both are strictly house cats. At first the kitten would launch attacks (jumping over the older cat, coming up behind it or just confronting it head-on) and the older cat would just hiss and use its front paws to try to swat at the kitten. This went on for about seven months and now the two get along pretty well with the older cat sometimes getting annoyed enough to hiss. The younger cat just simply runs circles around the older cat but I think this is good for the older cat as it keeps her moving. We never really tried separating the two and while they each have their own litter box and feeding bowl they both freely trade off. The younger cat likes rearranging the litter boxes by moving the litter all over the place.

You didn’t say what sex the older cat is and that may influence the situation. Both of our cats have been spayed (both before 1yo).

My personal belief would be to let them alone and see what happens. They now share our bed at night sometimes or they go there own separate ways when resting.

My friend would rub catnip on the kitten. It had no affect on the kitten but it would cause the older cat to enjoy the interaction.

I would expect a month of unhappiness. Eventually the older one will find the new cat is a playmate while the humans are away.

That’s my experience. I scolded bad behavior of the older cat and rewarded good behavior. I used a water spray bottle and cat treats.

While relating my own experience above, I also recall that my daughter has a household with two females (when first placed together the older cat was 8 years old and the kitten was about a year) that, after 4 years, still don’t get along and constantly hiss and fight.

I suspect that no generalization is possible as there are too many variables.

Take it slow and be patient. What Deegeea said is spot on. The feline rescue I work for recommends two weeks of separation/introduction. Some cats clearly indicate they’re ready before that (last time I introduced cats in my house it was 2 days), and some need even more time. I can’t stress being patient enough, though, if two weeks isn’t enough. I know several households where the cats have to be separated at all times or one returned to the shelter because they didn’t have enough introduction time and they just constantly fight. It’s far, far easier to take the initial time over trying to reverse damage once it’s done.