Updated November 28, 2020
Finding it hard to introduce a cat to another cat? Well before you feel like a failure, try this experiment…
Go to an image store and search for cat images. There should be thousands. Now search for two cats. There might still be a hundred or so, but look closer. You’ll see that the photos fit into only four categories:
- At least one of the cats is really a kitten
- The cats are so similar they are probably related
- They are eating or waiting for food
- They clearly don’t like each other
Finding a photo of two unrelated adult cats enjoying each others’ company is almost impossible. The photo above is one of the few, and even then these two still look like brother and sister. If you’re wondering how I can say this, visit our page on the sex-linked colours in cats.
So is it hopeless? Absolutely not. I’ve lived with up to four cats at a time without major problems. You might just need to adjust your expectations a little.
Why Cats Don’t Like Each Other
There are two strong evolutionary drives that stop cats being best friends:
- Cats didn’t evolve complex social skills: they started out as solitary hunters with almost no need to communicate in any meaningful way
- Cats see others as threats more than friends: their territory was their only food supply, so sharing or losing it could have been fatal
However, the last ten thousand years has brought them into contact with each other thanks to us. This has already brought changes we don’t see in wild cats. It’s like they’re now stuck between two worlds.
It’s the fact they’ve changed at all that makes it possible to encourage two cats to get along. The most critical time is right when a new cat arrives.
How Adult Cats Can Get Along
Although it’s rare to get two adult cats to be good friends, it’s quite reasonable to expect them to be happy living together. The decisions you make from the very beginning really matter.
Whatever you do, don’t just put the cats together and expect them to sort it out. Relationships are built on trust, so if aggression flares early it could ruin everything.
Introducing A New Cat
A typical two week plan is as follows:
- Put your new cat into just one room of the house, with food, water, litter, hiding places, and bedding. This will give the newcomer time to adjust to the move and the resident time to get used to the idea of a new cat around.
- Buy a Feliway® diffuser and plug it in in your existing cat’s favourite room.
- Make no further moves until both cats’ behaviour has returned to normal.
- Now start mixing scents by swapping objects from each space. These could be anything: furniture, bowls, rugs, bedding. These should be very interesting to each cat.
- Once this doesn’t bother each cat, start patting or grooming the cats with the same tools, gloves or wipes. This mixes their scents in a more ‘in-your-face’ way so only do it if it isn’t causing distress.
- Next, allow each cat to explore the other cat’s space without them seeing each other. Make sure that this, too isn’t a bother to either cat.
- Now start letting them see each other. Cats are highly visual so this is a big step. Create a gap smaller than a cat between the two spaces so they can check each other out, but withdraw if needed.
- Once this doesn’t bother them you can proceed with a full meeting. I would do it by feeding both cats in the same place (probably where the new cat is being lodged).
- You will need to be present for each early encounter and put the cats back when you depart. There will probably be a little hissing and staring but any interventions from you need to be gentle.
- Lastly, once encounters are always free of drama you can let both cats have full access to the house.
However, this approach alone isn’t enough for most cats. You have a high chance of failure if you don’t also consider some of the following:
Know Your Cats’ Temperaments
The gradual introduction method works best for cats of similar temperaments, either both shy or both outgoing. The worst cases of disharmony I see are when there is one of each. The shy cat can easily be terrorised by what the outgoing cat considers normal behaviour.
I don’t have easy answers for these cases so whenever possible choose cats who are similar to each other. Gender doesn’t seem to matter as much as temperament. When you don’t have a choice, some other ideas below will help too.
Make Resources Abundant
There needs to be at least two of everything, and preferably three. This includes food, water, beds, resting places and especially litter trays.
A particularly important resource is your time and affection. Not all cats need it equally, but you should be alert to their needs, especially those of the existing cat.
Enrich The Environment
The more complex the space, the less contact that cats need to have to deal with. This is especially important for resting places, which should be:
- only able to fit one cat
- have a good view or be secluded
- only be accessed from one direction
You can make lots of these and see which ones each cat likes.
I have written many, many ideas for making your house cat-friendly.
Keep Them Busy
Active cats are less likely to be stressed or fighting with each other. Although a mouse plague would be ideal, there is no shortage of ideas and products to keep cats occupied.
We all know this in theory, but when one cat attacks another, it takes a lot not to react. Any negative intervention from you only makes matters worse. Cats will learn to associate your reaction with the other cat.
Create Time Out Zones
Many cats are happier if they know that they can get away and have a snooze without worrying about the other cat. Here are some ideas:
- Schedule times of day when you shut a particular door in the house with a cat on each side
- Use microchip scanning cat-flaps so that certain rooms are only open to one cat
- Allow one cat to go outside during the day, preferably into a cat run
Exclude Other Cats
If you think things are already hard, wait until the neighbour’s cat works out how to get to your cat food. Or a stray cat starts staring at your cats through a window.
A strange cat will upset the delicate balance that is developing between your residents. Typically this quickly degenerates into ‘redirected aggression’ where aggression evoked by the stranger is turned onto the housemate.
Pictured are screens that an Adelaide client bought and fitted to stop cats inside seeing cats prowling outside. The effect was immediate.
Treat The Aggressor
If one cat is instigating conflict then you can tackle it directly. You need to be 100% sure so professional advice and videos are good here.
Once you’re certain, the aggressor can be asked to wear an ‘Elizabethan collar’ (the cone of shame), a loud jangly bell or a CatBib®. As a last resort I still occasionally use progestins for aggressive male cats but they carry a risk of diabetes.
Sometimes two cats will just never get along, just like two people. As sad as it is, you have to accept the reality of these cases and find a separate home for one of them.
However, with patience and care, nearly all cats will learn to get along. Most will just be happy to exist knowing there’s plenty of love, space, and food for all. A select few will be found sleeping together like the two at the top. If they do, send me a picture!
Related: Treating Anxiety In Cats
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story!
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