Are they both males?

My experience with introducing an adult female cat (2 yrs) into our
home, where we had a 7-year-old female has been really positive.

One key factor: what is your home like? Specifically, do you have
adequate space that they can each have a comfortable territory, and a
third "neutral" ground where they might meet? They might need this.

The dynamics: the 7-year-old female was raised from a kitten in a
one-cat home. Very spoiled, very much her own cat. Attacked any cat
that came up to the plate glass window, that sort of thing. She is a
big, burly spayed cat, and has her claws.

The rescue is a tiny female, very bright, very friendly, very used to
other cats from being in the shelter for four months. She is so gentle
she will not put out her claws when trying to escape our affectionate
embraces (!) but just squirms.

We live in a split level, and the bottom is where the 7-year-old hangs
out.
So I put the newcomers box and food on the third floor. Our kitchen is
on the middle floor. At first the cats stayed away from one another
and if we (stupidly, do not do this!) carried one into the other's
turf the incoming cat got very upset, hissing and growling.

Once we left them alone, they slowly got used to one another,
venturing into the middle area then into each other's territories, now
hanging out together, lying just a foot apart facing one another! But
it is now two years later. It takes time, and they do it in their own
time, and they must have comfy territories where they can be alone
without closing doors off. If you have one cat that is aggressive, let
him enter the other's territory, just watch them. There are generally
mutually vociferous spats with both cats retreating into their own
territories.

It took about a year before the cats were hanging out together
peacefully. Now, even after two years when the younger one approaches
the older and tries to sniff her butt in a friendly way (LOL!) the
older one rears up like a grizzly and swats at her. What is really
funny is that the younger one enters the older one's territory
sometimes by literally leaping down the stairs and vaulting over the
much larger older one, who then gives chase.

So: give them space, and time, and all should be fine. IF the same
applies to male cats, and IF your cats respond like mine. Big ifs, but
I hope my experience can help you. Good luck!

In article <wUiib.305432$Lnr1.225911
@news01.bloor.is.net.cable.rogers.com>, sylvie.lauzon@rogers.com
enlightened us with...

Oh, it can vary SO much, based on your cat's personality (and the
newcomer's).

It WILL be at least slightly traumatizing. You can minimize this by
introducing them slowly and giving them their own space in the home. It
can take a very long time for them to get along, though. Or, they could
get along right off the bat.

I adopted an adult male. I had two adult females. One female was very
okay with him inside of two months and they are really buddies now. They
cuddle and groom each other. The other female hated him with a passion
for nearly a year. They tolerate each other now and very occasionally
engage in mutual grooming. The male was exceptionally tolerant and never
started any fights, though.
Some males aren't like that.

There's a ton of info on the web about introducing cats. Just do a
Google search.

Good luck!

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~kaeli~
Jesus saves, Allah protects, and Cthulhu
thinks you'd make a nice sandwich.
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