We have three cats; Kittie, Trinie, and Cleveland. The first two are girls and are younger than Cleveland by about 4 years.

One of our cats ran away a month ago. I don't know how she got out but we couldn't find her anywhere. Yesterday she turned up in a neighbors yard, and then I brought her home.

I think Trinie is pregnant by the way she acts and her stomach is enlarged. (Trinie had a hernia when we got her as a stray so we were waiting for our Vet to okayed the spaying when the hernia was gone, that's why she never got spayed.)

But when we brought Trinie home, Kittie just could not stand her at all. She hisses, makes groaning noises, and runs away as soon as she senses her.

When anyone tries to pick Kittie up now she meows loudly like she's very annoyed she doesn't like anyone to hold her when she used to be very affectionate. I think she's acting like this because Trinie is pregnant?

I don't know but I sure do miss the old Kittie when she'd be so happy to see me...

Could this be also because Trinie smells different since she lived outside for awhile?

I hope that Trinie and Kittie can be as close as they were before Trinie ran away. They were best friends.

HOnestly,
First off, YOu should get all of your cats spayed or neutered. This helps them keep from wanting to stray. Secondly, cats are very different than dogs, they do not immediately accept new things,pets,smells etc. YOu should gradually introduce them together again however if she is indeed pregnant, then she needs to be separate from the others until after the kittens are born. It is rare that other cats will be okay with new kittens and often can end in fighting amongst adults and or injury to the kittens.