Introducing Cat to Kittens

Question
Hi Jillian,

I have a slight twist on this fairly common problem. My boyfriend has a male
neutered cat that is about 11 months old now. He and little Oscar has been
coming over to our house every other weekend because my bf doesn't like to leave
him at home and wants to see me as well. I just moved and on the first weekend,
my bf brought himself and Oscar. The next weekend I just recently got two new
kittens, 9 week old males brothers not neutered yet but will be!. The weekend
after that, I'd thought that it'd be a good time to introduce the three cats, in
hopes that they will all be friends. I placed the two kittens in a bedroom and
let Oscar have free reign over the apartment for a couple of hours. He seemed
interested but when he got over to their litter box he started hissing
immediately. We brought the kittens out in a carrier and Oscar again came up to
the carrier and started hissing again. We tried letting the kittens out and
Oscar was hissing, yowling, and growling. The kittens, at first, did not have
any feelings towards Oscar. One of them tried playing with him and Oscar would
swat him away but never really made contact. The other kitten and Oscar got
along worse than that. The other kitten would yowl and back away with his ears
completely back and start hissing at Oscar. We would separate Oscar into a
"safe" room whenever things got too tense or when he got too aggressive. We
tried multiple times over the weekend but Oscar would always give chase and
would always want to swat at them or go into pouncing position. He did actually
pounce on one of our kittens :( Finally, we just had to take Oscar back to his
own house. Do you have any advice on how to remedy this situation, if any? Are
there any possibilities of friendship between the three?

Thank you for all your help,

Crystal

Answer
Hi Crystal.  Congratulations on the new additions!  Of COURSE there are possibilities of friendship between the three.  However, there are certain things that you can do to make the friendship go more smoothly, so to speak.

The kitty that is being introduced should be isolated for at least a week so that the kitties can sniff each other under the door.  Even though your BF is bringing this cat over, it is a good idea to isolate him (in your bedroom or spare room or something like that) to make the transition easier.  Once the "new" kitty has been introduced to the others for a week (the sniffing under the door) then slowly introduce them to each other physically.  For my boys it took about a month to do this effectively - but that's also because I had 3 girls (now 4) so it made it a little more difficult because they were not neutered yet.  SO... if you do it slowly, it will work.  Now the boys (Remus J. Lupin and Sir Nicholas de Mimsy Porpington) are best friends with their sisters (well, maybe not Melody 'cause she's the Queen of the house and just sleeps all day!)

Good luck with the babes!