A dog and a cat under one roof: how to help them get along
Dogs and cats can live together perfectly well, and even sleep together. What almost never works is putting them together on day one to see what happens. The key is the pace, the particular dog, and the cat always having somewhere safe.
They don't hate each other: it depends on both
The idea that dogs and cats don't get on comes more from cartoons than from real life. Millions of homes have both, and many end up inseparable. What decides how they get along is, on the dog's side, its chase instinct: the urge to run after anything small that moves fast. And on the cat's side, its temperament and experience: a confident cat that has lived with dogs and doesn't bolt at the first opportunity makes everything easier than a fearful one that shoots off, because running away is exactly what triggers the chase. That is why the particular dog and the particular cat matter more than the species.
If the cat is the newcomer
When the dog is already at home, the cat is arriving in someone else's territory, with a big animal in it. Give it a room of its own, closed off, with a litter tray, water, food, a hiding place and high spots, where it can settle in peace for the first few days without seeing the dog. During that time, swap scents: rub a blanket or a sock on each of them and give it to the other, and let them sniff each other under the door. Once the cat is exploring its room confidently, let it wander the rest of the house while the dog is out or in another room, so it gets used to the dog's smell without having to see it.
If the dog is the newcomer
When the cat already lives in the house, the most important thing is that it doesn't lose its territory. Before the dog arrives, make sure the cat has high places, hiding spots, a feeding area and a litter tray that the dog can't reach. The dog is best kept to one part of the house for the first few days, with the cat free to use the rest. A puppy quickly learns to respect the cat if it is guided from the start; an adult dog that has never seen cats needs more time and more control. If you are adopting a dog, always ask whether it has been tested with cats: it is the most useful piece of information there is.
First visual contact
When neither of them reacts to the other's smell any more, visual contact begins, always with a barrier between them: a baby gate, a door held ajar with a stopper, a mesh screen. The dog should be on a lead and harness, and rewarded with food when it is calm and looks away from the cat, not when it stares, because then what it learns is to fixate. The cat should be free to leave and have a high spot to watch from. Keep sessions short, a few minutes, several times a day, and end them before either of them gets worked up. If the cat hides or the dog won't take food, you need to slow down.
In the same room
Only once the dog can ignore the cat with the barrier in place, repeatedly and for several days in a row. At first, keep the dog on a long lead that you can step on, so you can stop a chase without shouting or running after it yourself, which is what turns a fright into a dangerous game. The cat must always have high escape routes, and never be cornered in a hallway. Let the cat be the one to approach if it wants to. And never leave them alone together until you have had weeks of total calm; if the dog has a strong chase instinct, keep them apart whenever nobody is home, and don't see that as a failure.
Keep the cat's territory safe
There are three things of the cat's that the dog must not be able to reach. High places spread around the house, so the cat can move about up high without coming down to the floor. Its food: dogs love cat food, which is fattier and richer in protein, and a cat whose food gets stolen or whose meals get interrupted ends up eating badly. Put it up high or in a room with a cat flap. And the litter tray: many dogs eat from the tray, which is unpleasant and carries a risk of parasites, and a cat that doesn't feel safe in its tray starts going outside it. A cat flap, or a door with a stopper that only lets the cat through, solves all of this.
Which dogs tend to do best
Those with a low chase instinct and a calm temperament: many companion breeds, retrievers, some calm mastiff types and many greyhounds, though not all, which rescues often test with cats before rehoming them. Terriers are riskier, because they were bred to hunt small animals; scent hounds follow anything that moves; and herding dogs may try to round up the cat, which it won't find funny at all. There is huge variation within every breed, so an adult dog that has been tested with cats is worth more than any list. And on the cat's side, confident adults that don't run off cope much better than kittens or very fearful cats.
How long it takes and how to tell it is going well
From two weeks to a couple of months, depending on the two animals. It is going well when the dog stops fixating on the cat, when the cat comes down from its high places, eats and uses its litter tray normally, and when they ignore each other or seek each other out without tension. It is going badly when the dog goes rigid, staring fixedly at the cat with its body leaning forward, which is the prelude to a chase; when the cat hisses often, lives in hiding, or stops eating or using its tray; or when there is chasing. If things haven't improved after several weeks, go back a stage or two and ask for help from a vet who specialises in behaviour or from a trainer.
Kittens, puppies and special cases
A puppy and a kitten that grow up together usually get on very well, but watch the size difference: a large puppy that plays roughly can hurt a kitten without meaning to, so supervise and separate them when play gets out of hand. With an elderly cat or one in pain, such as a cat with arthritis, a young, heavy dog can be a constant source of stress: give it even more protected spaces. And if the dog has a history of attacking cats, living together may not be possible, or may require long professional work. In those cases, the cat's safety comes first.
They can certainly live together, but not on day one. Swap scents, make first contact through a barrier, reward the dog when it is calm, and give the cat high places, food and a litter tray the dog can't reach. Take your time, and don't leave them alone until you have had weeks of calm.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.