How to Introduce New Pets to Existing Pets

How to Introduce New Pets to Existing PetsPets, in their deep instinctual psyches, have a distrust of strangers, individuals from outside of their tribes or extended families. Animals are individuals, each with his and her mixture of genetics and early environmental factors, almost like human beings. Any instructions about handling animals always come with the proviso that you have to avoid complete generalizations, and look at the behavior of each individual.

Here are some ways to ensure that you choose a pet that has a better chance of getting along with your existing pets, and some tips for weathering the transition smoothly.

Selecting a New Pet

  • Find out about the background of the dogs or cats you are considering. If the dog or cat has had the experience of living peacefully with another, that could be a signal that the introduction could be easier.
  • In most cases, it is probably not a good idea to add a pet to a household of pets if the cat or dog has had traumatic or painful experience.
  • The personality of the cat or dog is also important. If the prospective pet seems to want to be alone, it may be harder to integrate him or her. If they seem playful, then moving them in with another sociable animal might work better.
  • Try to match dogs or cats who have similar habits. If the resident animal just likes to lie in the sun all day, selecting a second pet with similar proclivities might be a good idea—they may spend sunny afternoons lying quietly.
  • Getting a puppy or kitten is not always a good idea if the resident cat or dog is old and grumpy or likes a solitary life style. Young animals often want the attention of older animals for nurturance and protection and unprepared older residents may perceive these attentions as more than an annoyance.

"Finding out as much you can about the background of the #cat or #dog you're considering adopting is more important than ever when you have existing pets." TWEET THIS


Dogs have very strong territorial instincts. The resident dog will act aggressively at first to defend the home from strangers. The introduction of a new dog can be a long and difficult journey. You will have to have the time and energy to cope with it step by step. Here are some tips:

  • When the new dog comes into the house, separate the dogs so there is no visual contact, but the scent is available. Dogs live in a world of scent and they can be introduced using their smell sense without having visual contact. 
  • Place the dogs in two crates, or closed rooms in separate areas of the home. Place a toy or blanket belonging to one dog within sniffing range of the other as "scent articles." Exchanging scent articles will allow the dogs to meet by smell.
  • Let the new dog roam around the home for 15 or 20 minutes several times a day to allow him or her to get accustomed to the new place and the group of humans that share it with him or her. The new dog will also be leaving his or her scent in the space that will eventually become his or her own.
  • Switch the dogs. Confine the new dog and allow the old dog to play. This can be a very confusing time for the old dog. Human reassurance is going to be important during this period.
  • It is best if the first face-to-face meeting between the two dogs not take place on your property or space, but on neutral ground. It should take place in an enclosed area (your neighbor's fenced-in yard for instance). This kind of neutral ground meeting will allow the dogs to develop friendly relationships and establish roles with each other safely.

BONUS: How to Introduce Your Pet to Your New Baby


  • Before bringing the new cat home, create a separate space for them. It should contain multiple hiding places, water, feeding dishes, scratching posts and a litter box.
  • All the cats in the home should have their own territory, equally equipped.
  • Hiding places are important. Cats always need a place to retreat to when confronted by other cats.
  • In the initial period, spend time with all the cats, observing them and looking for signs of stress.
  • Once the cats appear comfortable in their spaces, place the new cat out of his or her private space and allow other cats to enter so they can get familiar with the new cat's scent. This acclimation can take place over a day.
  • Then let the cats get familiar by sensing each other through a closed door. After they seem comfortable with each other, allow them to meet by opening the door. Observe them carefully.
  • With any sign of stress, separate the cats and allow them to meet again more slowly.
  • Over multiple sessions, reward the cats with treats when they are in each other's presence.
  • Patience is a virtue when introducing cats to each other.

South Boston Animal Hospital is a family animal hospital. We love to care for your furry friends like they were part of our own family. We will work with you and your pet to evaluate any individual situation so that we can come up with a personalized solution that is right for you. Please contact us to learn more.