Introducing two adult cats

Question
Hello Norman,

My boyfriend and I have decided to move in together and we both have 2 adult male cats.  Milo is 4 and Buddy is 6.  I'm nervous about them not getting along and fighting.  Milo has lived with two other cats before and after a few days they got along just fine.  Can you recommend how to make a smooth transition for our cats from becoming strangers to pals?  What is the best way to introduce them to each other preventing a fight?  Your response will be greatly appreciated!

Tricia

p.s.  Milo will be in the new home two months before Buddy arrives and am concerned about him becoming territorial.  

Answer
Tricia,

Treat Milo as the established cat in the following.  Below is a procedure which allows for a smoother transition for a cat coming into a household with an established cat.  Given Buddy's and Milo's ages, the transition to getting along may take a little longer:

Start out your new 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 new cat will not be overwhelmed by its new surroundings and get "lost", and thusly will have no problem finding the litter pan (often kittens or rescue cats have been confined and are somewhat daunted by wide open spaces!). You will feed the new cat in this room and keep the established cat out. It allows the new cat to 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 new cat and the established cat to sniff each other under the door and get familiar with each others' scents.

After 5-7 days of being in its one room, it is time to let them 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 cat treats and extra attention after the new 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.