For starters, set up a separate room for the new cat. One room is best to begin with as the cat needs to acclimate to this totally new environment of place with all the novel infrastructure and attendant sights, smells and sounds (including you). Limiting the new environment to one room will enable the cat to navigate this uncharted territory on a smaller, less stressful scale. Remember to offer a cat bed, perch, scratching pad or post, toys, food and litter box (keeping the litter box a good distance from the food and bed). Do not be alarmed if there is a lot of hiding initially, this is normal, the cat needs to get acquainted in this new place with the environment and to trust in its safety and this can only happen with the passage of time. (More on welcoming a new cat and the extra steps a feral or former feral may require.)
Resident cats may display little or no interest in a closed off room, unless of course, this is a room they have been using. If your original cat sleeps with you every night, installing the newcomer in your bedroom will be problematic for the resident cat, so please consider the best room for all concerned. To facilitate the adjustment process for each cat, resident or newcomer, keep in mind that cats are extremely sensitive and reactive to changes in environment. As we are a part of their environment we can be instrumental in familiarizing them to both new situations and individuals. Follow these guidelines for success:
Start by being a calm and soothing presence. Your body language, eye contact and tone of voice will set the tone for each and every encounter. Remember to always announce your presence and acknowledge the cat with a greeting coupled with the use of their name. Begin with first acknowledging your resident cat when you enter your home and/or a room they are in. Keeping the cat who came first also first in your interactions can help. Your affection, attention and engagement are just as much of a resource as raised resting places, litterboxes, etc., to appropriately distribute.
Along with a soft and gentle tone employ an approach from the side rather than facing directly in front of the cat, this is perceived as less threatening. Lower yourself to cat level and offer hands for petting from below where they can be seen by cat eyes. Avoid direct eye contact but do try a slow and steady blink which is an affiliative response in cats.
Avoid any punishment -no scolding, scat mats, spraying with water bottles or shaking noise-makers of any kind, Punishment is cruel, highly stressful, interferes with learning or creating positive associations. Always remember that cats do not respond well to correction or harsh treatment and tend to associate that event with the person and new cat instead.
More cats? More cat furniture throughout. Allocate resources generously and evenly. Litter boxes, water and feeding stations and cat furniture need to be easily accessible for each cat. Experts recommend, with good reason, at least one raised resting space and one floor space (igloo/box/bed) per cat. With cats being both prey and predator, retreat from danger is more than innate in their behavior. Cat trees and shelves placed properly, especially against walls, corners and mazing next to windows to allow cats to look outside, from a high vantage point and survey their interior and exterior world safely.
Adding more horizontal resting areas expands cat territory for that sometimes necessary hiding/alone time needed in a multi cat household while offering more cat friendly areas for cats to share or time share. That placement of a cat tree (or a cat shelf) next to a window or on a corner wall will enrich their world tremendously (more on making a cat friendly home). Don't forget to distribute this resource to every room and when thinking cat beds, favor their favorites - boxes that come in the mail and play tunnels that appeal to all ages. Create positive associations at every turn.
Add more scratching and foraging opportunities too. Sturdy cat scratchers, corrugated cardboard or sisal scratch pads with catnip/valerian root) rubbed in offer a soothing and stimulating experience especially beneficial around the presence of another cat. Offset some of the stress of changes by providing all of your cats' dry food in a puzzle feeder to offer engagement and allow for natural behaviors. Selecting a feeder that is both large enough and positioned so both cats can freely access it can also offer another opportunity for more positive associations around each other.
Begin interactive play time with all cats. Take two-four minutes each morning and in the evening and play with your cats using an interactive toy. Fishing wand toys where you can engage the cat by drawing a lure across or away from their line of vision are best. (The lures on these wands vary from feathers to objects to cardboard pieces you may need to try several to see what best attracts the attention of your cat.) Always start playing with your original cat first.
For the first week or so play with your newcomer in the room they are in without asking for any other interaction (unless actively solicited). Try to stage your play sessions with your original cat as close to the door of the newcomer’s room as possible. Should your resident cat seem more interested in the door than in playing try moving away from the door to get the attention back on play. You can work on moving forward later in the process. (This can also be done by two individuals playing at the same time with each cat.) Keep interactive play sessions as close to being on schedule as possible - cats benefit from the sense of control schedules provide but make sure they happen. Hide fishing wand toys when not in use.
Cats rely heavily on scent to process their environment. Scent exchange is a great way to introduce the residents to the newcomer and vice versa. Try using soft cat toys (and at least one catnip filled toy) and rub the toys behind the ears of the cat, along the muzzle, on flanks and base of tail. Exchange cat scented toys in each area. In addition to exchanging cat scents with the toys, add yours to the process: A small piece of clothing from the bottom of your hamper (you can skip rubbing this behind human ears since it is already scented) can be rubbed along cat areas noted above and one item left in each cat area. Scent exchange should begin right away
After the first week of the above progress to supervised interaction, play in eyesight of each other. Install removable baby gates in the door of the newcomer— one on top of the other. While the gates are in place practice this routine: (Continue reading below).
