How Should I Introduce New Pets to My Resident Pets?

There are many factors to consider when introducing pets for the first time.

Factors to Consider

The species, breed, size, gender, age, individual temperament and health status of each pet all contribute to their initial encounter and eventual coexistence. With so many factors to consider, it is virtually impossible to predict how one pet will respond to another.

Not all dogs and cats are destined to be antagonists. Not every sexually intact (uncastrated) male will reject a new male in its territory. If you already have a dog (or cat), adding a second one of the opposite sex does not guarantee they will get along.

Sometimes the most unlikely pets become instant and life-long companions. Sometimes the intolerance of one or both is immediate and enduring. Often the initial period of conflict evolves over time toward a minimum of mutual tolerance. Also, once-stable relationships can degenerate for a variety of reasons. Here are some general guidelines for introducing a new pet to resident pets:

Take your time. A gradual process of discovery and investigation is best.

Spend extra “quality time” alone with each pet during the transition period. Reassure your resident pet and establish bonds with the new pet.

Watch for impending fights. A smaller pet is in more danger from injury by a larger pet than the reverse. A dog attack is more likely to severely injure a cat than a cat’s attack on a dog.

Give a frightened animal an avenue of escape. Fights can result in intentional or unintentional injury of anyone preventing retreat or blocking the path to safety.

Consider your own safety before interfering with aroused or fighting animals. Proceed with caution but recognize that you could be injured.

Also see How Dogs Think.

Return to top.

Introducing a New Cat to a Resident Cat

Cats that have been exposed to other cats while growing up may adjust more readily to a new housemate. The best way to avoid conflict between cats is to carefully prepare for the first encounter. The resident cat may adjust to the newly introduced cat without confrontation if they are first required to share your home but at different times of day, and are not immediately introduced. For the first few days, keep the new cat confined to one room. Provide fresh food, water and litter daily. Make frequent visits to spend time playing, feeding, petting and generally interacting with the new cat during its isolation. Give it time to adjust to this one location, where it is guaranteed emotional and physical security. This will also help you establish a positive relationship with your new pet without distraction.

Meanwhile, your resident cat will sense traces of the intruder on your clothing and skin. The new pet’s odor and sounds will alert your resident cat to its presence. During this period, spend extra time with your resident cat, engaging in favorite activities in an effort to relieve any anxiety and minimize tension.

Feeding tends to relieve an animal’s feelings of anxiety and may help it adjust to the household changes. Place your resident cat’s food dish near the door to the room where the new cat is kept confined. Gradually move the confined cat’s food dish closer to the inside of the door. Feed them at about the same time so that they are separated only by the closed door. Move to the next step when neither cat exhibits any growling, hissing or spitting when it senses the other is nearby.

Next, confine your resident cat, with its own food, water and litter box, to a favorite location. Your own bedroom may be convenient; most resident cats feel comfortable there because it is associated so strongly with you. Allow your new cat to explore your home for brief periods. Accompany it on its patrol to extend the comfort of your presence beyond the room where it had been isolated.

Several times each day, allow the new pet out of confinement for longer and longer periods. When both cats appear comfortable (the new one will assume positions of rest, for example, or groom itself more than it actively explores your home), proceed to the next step.

It may take several weeks to reach this point. Even if it takes only a few days, delay the next step for an additional week. Keep separate litter boxes for now. With continued progress, you may decide to gradually move one or both litter boxes to another location. It is advisable to maintain one litter box for each cat, even though each cat will likely use both boxes.

Arrange to be present when both cats roam freely throughout your home for the first time. This should be planned to coincide with regular mealtimes. Follow the new cat so that you will be present when they first see each other. Some hesitation and hissing are to be expected from either or both individuals. Feed the cats in each other’s presence, placing their food dishes at a comfortable distance. Wait only a few minutes after they have eaten to confine the cats to their quarters until the next scheduled mealtime. If either or both cats seem so disturbed that they do not eat in the other’s presence, remove the food bowls and confine each to its own safe place.

Try again when both cats are calm. If a second attempt fails, remove their food and confine them again. Wait until each has regained its composure to feed it. Try again the next day. As things settle down, allow them to spend progress ively longer periods together after they have eaten each meal. Move their food dishes gradually closer to each other at successive meals. If problems occur at any time during the introduction process, return to the preceding step as outlined above.

Be patient. Some cats are less sociable toward others and less willing to share their territory. If the cats are consistently aggressive toward each other, it may be necessary to treat one of both cats with homeopathy to help with acclimation. Daily use of Rescue Remedy, Feliway, or similar may be needed. As a very last resort, mild sedatives or even psychoactive medications can be prescribed by your veterinarian. Use these only if absolutely necessary and for a short time. Both cats are likely to experience some anxiety during the transition period, though one cat will likely react more strongly than the other. Unless there is a medical reason not to use medication or one cat seems completely unbothered by the other, both cats are likely to benefit from medication.

With time, most cats learn to accept others in the household. Should your cats be exceptions, however, three options remain:

Keep one cat confined for part of the day, while the other roams freely.
Keep one cat permanently confined to one part of your home, while the other is kept exclusively in the other. You can always try another introduction later. Or you may have to:
Find another home for the new cat you had hoped to adopt.

Return to top.

Introducing a New Dog to a Resident Dog

Dogs are best introduced with both dogs restrained on a leash. If you are confident of your resident dog’s good nature and good social behavior, you may not need the leash. Unless the new dog is a young puppy or juvenile, it is probably best to use a leash.

Ideally, introduce the dogs on neutral territory that is unfamiliar to both dogs or where neither one has been for long. If this cannot be conveniently arranged, let them greet on the outside perimeters of the resident dog’s territory. This may be in your neighborhood at a distance from your home. In the heart of your dog’s territory, such as inside your home, conflicts are more likely to occur.

Though it is difficult to predict how dogs will interact, most adult dogs tolerate the clumsiness of puppies and juveniles. Problems are more likely between two adult animals when one or both have been unfriendly toward other dogs.

As much as possible, place the new dog in a “down/stay” position in the resident dog’s presence. Teach the new dog to accept a submissive position in deference to your resident dog, creating a clear basis for their relationship. This should help control their initial encounter so that they can gradually work out their social status by subtle challenges and with only minor conflict later.

If problems escalate, separate the dogs and slowly reintroduce them under careful supervision. In cases of extreme aggression by either or both dogs toward the other, it is probably not worthwhile to proceed.

Also see How Dogs Think.

Return to top.

Introducing a New Dog to a Resident Cat

Cats that have had positive experience with dogs early in life are more likely to welcome a new pet dog. Before introducing a cat to a dog, it is important to determine if the dog will harm the cat. Some adult dogs that have never previously seen a cat show no aggression toward one. If a dog’s predatory instinct toward cats is strong, however, it is likely to be displayed immediately and with little advance warning. For this reason, restrain the dog on a firmly held short leash and do not allow the cat to come within the dog’s biting range.

If you have adopted an adult dog, if possible, ask the previous owner about the dog’s previous interactions with cats. If the dog has had no previous contact with cats, proceed with caution. If you have acquired your new dog from a local shelter, ask the staff to test the dog’s tolerance to cats before you take it home.

Even if there is no reason to suspect a problem, you should still restrain your new dog when it meets your cat. Young puppies (younger than 3 months) are unlikely to harm an adult cat. Though there are always exceptions, young animals are unlikely to turn against other animals when they are raised together.

Also see How Dogs Think.

Return to top.

Introducing a New Cat to a Resident Dog

Most of the guidelines suggested for introducing a cat to a dog apply here. Proceed cautiously. As long as the dog is restrained on a leash and the cat is free to escape, rely on the dog’s initial reaction to the cat. If your dog guards its food or other objects, retrain it or take preventive measures. A cat that approaches a dog guarding its food may risk injury.

A common concern among dog owners is that a cat will scratch their dog’s face and, in particular, its eyes. This concern may be less common when an unfamiliar dog is introduced to a resident cat.

A cat will rarely attack a dog without provocation unless it is cornered or threatened. Most dogs have a long muzzle and quick reflexes that adequately protect their eyes from cats. Your dog’s eyes are more likely to be injured from flying debris when its head protrudes from your car window. Any traumatic corneal lacerations caused by a cat usually heal well with veterinary care.

Return to top.