Reintroducing my newly found lost cat back into the household

Question
Hi there, I currently live in a 1-bedroom apt. and I have a few kitties. They're all sweet and got along fine together. About 4 months ago, while I was traveling for work, my mother was taking care of my kitties and one of them (who loves to be outside) slipped out and went missing. The good news is, I found her today in an adjacent apartment complex. Apparently she had been living off the generosity of the community, one of the neighbors had even dewormed her and took her to get her shots. Anyhow, I've brought her back home and now all the cats are puffed up and growling at each other. I realize they probably don't recognize each other's scents anymore, so is there anything I can do to help de-feralize my sweet kitty?

Answer
Pixie,

I will give you a tried and tested technique we use to introduce a new kitty into a household with already established cats.  Since these cats have known each other before, you may be able to shorten some of the timings, but I would proceed with caution as these are all adults:

Start out your lost cat in one room with a litter pan and water dish.Ideally, the one room should be a bedroom with yourself or another human resident. This accomplishes a couple of things. Your lost cat will not be overwhelmed by its new surroundings and get and, thusly, will have no problem finding the litter pan. You will feed the lost cat in this room and keep the established cats out. It allows the lost cat to re-bond with you or another human being and also build up some self assurance in its new surroundings since it will not have to compete for food or attention right away. Finally, it allows the lost cat and the established cats to sniff each other under the door and get familiar with each others' scents.

After 3-5 days of being in its one room, it is time to let everyone meet each other. Be prepared for some posturing, some spitting and hissing, and the like. IGNORE IT! After a while, they should begin chasing each other about and still have the occasional hiss or spit as they get accustomed to each other. Cats tend to make a whole lot of noise and even loosen up some fur. Rarely will two cats hurt each other.

Once they are introduced, there are a couple of things you must remember. Do not separate them again, they will get along! Do not interfere in their "discussions" as they need to sort it out amongst themselves!

It does not hurt to give the established cats treats and extra attention after the lost cat is introduced (yes, cats do get jealous!).

A couple of things you may have to do are to feed them on separate dishes. Provide more than one litter pan in different areas of the household (as cats can be very territorial about litter pans).

All, in all, this method seems to have had great success in the past and makes for a fairly smooth introduction. Please remember that they may make up immediately, or it may take a few weeks.

Best regards... Norm.