How do I introduce a new cat to my existing cat?

twocatsCats are extremely sensitive to changes in their environment. Some cats can meet a new cat and be friends right away, but cats are very territorial, and most cats need time and space to adjust to a new companion and establish a rapport and a new social hierarchy.

All cats are different, so there is no hard and fast rule regarding how long it takes to introduce a new cat into a home with an existing cat, but it may take up to 4 to 6 weeks for the cats to make the adjustment. If at any point the introduction fails, you have to take a step back or start over altogether.

Step 1: 1 – 2 weeks

Keep the new cat in a separate room, such as a bathroom or bedroom. Do not let them see each other. This will allow your new cat to get used to the sounds and smells in their new environment without encroaching upon your existing cat’s territory.

Feed the new and the existing cat wet food or special treats on either side of the closed door. This allows them to hear and smell, but not see, the other cat. Getting a special treat in the presence of the other cat builds a positive association with the other cat’s presence.

Take a pair of socks and rub the cats down with them, then lay one sock by each cat’s food bowl. This continues to build a positive association with the other cat. Re-scent the socks every 3-5 days.

Rotate the cats into each other’s territory for a few minutes at a time (without letting them see each other). Put your existing cat into the new cat’s room after you have removed the new cat, then let your new cat explore the existing cat’s territory.

Step 2: 1-2 weeks

Continue to do all of the above, but now let the cats have brief glimpses of each other. Hold one cat, open the door for a few seconds so they can see the other cat, then shut the door. Do this a few times a day, and make it just a little longer as you progress. You can also put the new cat in a carrier and set it out in the existing cat’s area for 30-60 minutes at a time. Some people put up a screen door between the two rooms during this time so the cats can see each other, but still remain safe.

Step 3: 1-2 weeks

Now it’s time to see how they do together. Make sure you have a large open space with escape routes in case either cat gets nervous or needs to flee. Put each cat at either end of the room, and have a squirt bottle of water at the ready in case you need to break up a squabble. Let them have supervised time to interact and explore and see how they do. Once you are satisfied that they have had several successful visits and seem to be getting along, you can try leaving them unsupervised.

If you have followed all of the steps, have taken it slow, and took a step back (or started over from the beginning, if necessary), your cats should be able to cohabitate peacefully, and may even become good friends.

Not all cats, however, will get along. Just like people, some cats just won’t mesh. In this instance, you can try the following:

  • Feliway diffusers (30 day plug-in)
  • Feliway calming spray (sprayed 1-2 times per day)
  • Calming collars (30 days)
  • Rescue Remedy (added to drinking water)
  • Prozac (for anxiety/aggression; it can take 4-8 weeks for the drug to have an effect, but cats may not need to be on it permanently)
  • Keeping the cats in separate parts of the house or rotating them

Also make sure you are following the normal rules of thumb for cats:

  • One litter box per cat plus one extra (in different parts of the house)
  • Separate food and water areas for each cat
  • Make sure food and litter stations won’t cause one cat to become trapped by the other cat

If all methods fail and you find yourself unable to keep the new cat, please return it to the rescue group you adopted it from (or find a rescue to take it in if you acquired the cat elsewhere). Please don’t turn it in to a kill shelter or animal control facility. Owner surrenders do not have a hold time and may be put down immediately. Very few cats make it out of kill shelters alive. Please don’t dump the cat outside, either. The outdoor environment is harsh and dangerous; the cat will not thrive, and may not survive. Cats who are allowed outdoors have a significantly shorter life expectancy on average than strictly indoor cats.

For a listing of local pet resources and organizations, click here.

Click here to download a printable version of this guide.

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