When adding any new pet to your family, the first step is to pick the best possible fit given your household dynamic and lifestyle. All cats are individuals, just like us. Some cats will be comfortable and mesh into your household better than others. It is important to learn as much as possible about the individuality of the cat before making any decision. Speak with those that have spent time with the cat over an extended period of time and had the opportunity to observe the cat in a variety of situations (around other cats, new people, and just basic alone time). Get their feedback and insight.
The most respectful thing we can do for any animal, is to put them in an environment that will meet their specific needs and desires. Not ours. Do they like to interact with other pets or people? What brings them joy and fulfillment? How sensitive are they to change, high energy, other animals? Learning what will provide the most fulfillment for the animal isn’t always easy, but it is a necessary part of the process in order to reduce potential problems such as unnecessary stress, injury or a possible return.

 

CREATE A SAFE SPACE FIRST:

Even if the cat you are adopting is good with other cats, there is no 100 for any living being. There is always the possibility of problems when introducing strangers to each other. This goes for humans, dogs and cats too. There are several steps that you can take to reduce the likelihood of problems. Before bringing your new cat home, create a separate “safe space” for him/her. This area should be comfortable and quiet with food, water, a scratching post, a litter box, places to hide, comfortable places to rest, access to natural sunlight, and is safe from other animals.
Your other cats should have their own separate space. Make certain that both areas (the space for the new cat and the space for the other cats) contain multiple hiding places so the cats can easily retreat if necessary. Large cardboard boxes with holes cut in two sides make great hiding places. The second hole allows the cat to escape if cornered by another cat. The boxes will come into play once you start allowing the cats to interact directly, but it can be helpful to introduce the boxes first, so that the cats become accustomed to using them.
Place your new cat in his/her space as soon as she arrives home and spend good quality time with them there each and every day. Play with them regularly and watch them closely for signs of stress or anxiety, such as hiding, aggressive behavior, decreased appetite, and/or excessive vocalization. If you see any of these signs, your cat could be suffering from stress. If the signs persist for more than several days and/or if your cat stops eating, consult with your veterinarian.
If any cat is showing mild signs of stress, give him or her time to acclimate to the new situation. If all the cats appear comfortable in their spaces, place the new cat in a different room (equipped with the same amenities) after two days, and allow your other cats to enter the new cat’s original territory. This will allow each cat to become accustomed to each other’s scent in a non-threatening way. Allow the cats to acclimate to their new areas for a couple days.
Take your time with this process and transition. There is no rush. Like all new relationships, each cat involved will need time to learn the other. Some cats (like people) will need longer than others. Careful observation on the humans’ part is necessary throughout the entire introduction process. Your new furry companion will so appreciate you for it!

SCENT TRANSFER INTRODUCTIONS ARE MORE SUCCESSFUL:

Here’s a special tip that we loved from one of our partner shelters! We do scent transfer with dogs too!
Cats have glands in their cheeks that produce pheromones. When your cat rubs her cheek against a wall, chair, or your leg, she produces pheromones, which are chemical substances that can help to relieve anxiety and provide information about the cat who is producing those pheromones. Exposing each cat to towels that were gently rubbed on the new cat’s cheeks may be a good way to introduce them. Some cats respond very well to a synthetic pheromone (a spray or diffuser), a product that can be bought online or in pet supply stores.
Next, you can start allowing the cats closer access to each other by placing them on either side of a closed door so that they can smell each other directly. The next step is to allow them to see each other through a baby gate or a door that is propped open two inches. If the cats are interested in each other and seem comfortable, allow them to meet. Open the door to the rooms between the cats and observe them closely.

THERE IS NO 100:

As with any live being, there is no 100. We are all living breathing organisms and that means, we are not always going to be at our very best. As humans we have good days and bad days. Animals do as well. An anxious cat is much more likely to behave aggressively than a cat who is comfortable and relaxed. If you use patience in the initial stages of the introduction process, you will probably increase your chances of a harmonious household.
If you have tried the techniques above and your cats are still not getting along, please seek the help of your veterinarian or a behaviorist.