Introducing a Second Pet: How to Do It Without a Fight

Introducing a new pet home can be very exciting‚ but introducing the new pet to a resident pet too quickly can be very stressful‚ as one of the animals will often hide and the other will become defensive when put in the same room․ This is how most difficult introductions of pets begin, but most problems can be fixed by going slow and giving both pets time to adapt.

Take the newcomer to a vet first, especially if it came off the street. This should include a general check, deworming, tick treatment, and testing for relevant infections. For cats, that means asking about feline leukaemia and FIV before the two animals share a space. Keep the new one separate for the first week or two anyway, which doubles as quarantine and as a settling-in period.

Then set up the resident pet so it loses nothing. New bowls, a new bed, an extra litter tray, and an extra water bowl in a different room. Almost all early conflict is about resources, not personality.

This is the introduction that most needs patience, and rushing it creates a grudge that can last years.

Start with the new cat in its own closed room with everything it needs. For the first few days the two cats only smell each other under the door. Swap bedding between the rooms, and rub a soft cloth on one cat's cheeks and leave it where the other sleeps.

Next, feed them on either side of the closed door, moving the bowls slightly closer each day. The point is that the other cat's smell becomes associated with food rather than threat. Then allow brief visual contact through a door held ajar or a mesh screen, ending each session while both cats are still calm.

Only then let them share a room, briefly and with you present, with escape routes and high perches available. Gradually increase the time to a few minutes. Two to four weeks is normal. Some pairs take longer, and forcing the pace is what turns caution into hostility.

Dogs do better with a first meeting outside the home, because a dog defends its own territory and does not defend a road it has never seen. Take both on leashes, with one person per dog, and walk them parallel a few metres apart in the same direction without letting them meet head-on. Let the distance close gradually over
the walk. Keep leashes loose. A tight leash tells a dog that something is wrong. When they do greet, keep it to a few seconds, then walk on. Then walk home together and let them enter separately.
Indoors, feed them in separate rooms for the first few weeks, pick up toys and chews that might be guarded, and give each dog its own bed. Supervise every interaction until you are confident, and separate them when you go out.

This is dependent on the dog's prey drive and the cat's ability to escape, but start off by keeping the dog and cat separate and swap their scent. When they first meet, restrain the dog and let the cat leave the room and perch up high. Do not hold the cat while letting the dog go to it․

Reward the dog for looking at the cat and then back at you; for that is the behaviour you want. It is a fact that sighthounds and other breeds with a higher prey drive may not always be left alone with a cat․

Good signs are relaxed bodies, eating normally in each other's presence, sleeping in the same room at a distance, and ordinary curiosity. Hissing, growling and a swipe with the claws are communication, not disaster, and often settle.

Stop and slow down if you see a hard stare with a stiff body, a cat that stops eating or stops using the litter tray, a dog that fixates and will not look away, hiding that lasts several days, or any fight that draws blood. Repeated real fights need a behaviourist, not more hope.

Small houses make the task more difficult because there is nowhere to retreat․ Think of height rather than floor space – a shelf, a cupboard top, a cat tree. With dogs, use a crate or closed room as R&R (rather than punishment) to keep them away easily. With cats, consider netting balcony grilles; a stressed cat will find a way out and be obsessed by it.

Two to four weeks for most cats, often faster for dogs. Some pairs take a couple of months, and taking your time is free.

Opposite-sex pairs tend to settle more readily than mixed-sex pairs, but sterilisation and temperament are more important.

Keep its routine intact: same time for walks, same place for meals, same time in your lap (most jealousy is really just a change of routine)