Animals that live in groups, like dogs, establish relationships, through which the individuals involved interact and live together. The roles that the individuals play within the relationship can change with each new day or situation. These relationships also take time to build, so proper introductions are important to help the dogs adjust to one another and start to build on their relationship.
Introducing New Dogs to Resident Dogs
Choose a Neutral Location: Introduce the dogs in a neutral location so that your resident dog is less likely to view the newcomer as an intruder. Each dog should be handled by a separate person. With both dogs on a leash, take them to an area with which neither is familiar, such as a park or neighbor’s yard, or you can go for a walk together. If adopting a new dog from a shelter, we recommend bringing your resident dog with you to the shelter and introducing the dogs before adopting.
If you have more than one resident dog in your household, it is best to introduce the resident dogs to the new dog one at a time. Two or more resident dogs may have a tendency to “gang up” on the newcomer.
Use Positive Reinforcement: From the first meeting, you want both dogs to expect “good things” to happen when they’re in each other’s presence. While keeping the leashes loose, let them sniff each other, which is a normal canine greeting behavior. As they do, talk to them in a happy, friendly tone of voice – never use a threatening tone of voice. After a short time, get both dogs’ attention, and give each dog a treat in return for obeying a simple command, such as “sit” or “stay.” Take the dogs for a walk and let them sniff and investigate each other at intervals. Continue with the “happy talk,” food rewards, and simple commands.
Be Aware of Body Postures: One body posture that indicates things are going well is a “play-bow.” One dog will crouch with her front legs on the ground and her hind end in the air. This is an invitation to play that usually elicits friendly behavior from the other dog. Watch carefully for body postures that indicate an escalation in response, including hair standing up on the other dog’s back, teeth-baring, deep growls, a stiff legged gait, or a prolonged stare. If you see such postures, interrupt the interaction immediately by calmly and positively getting each dog interested in something else. For example, both handlers can call their dogs to them, have them sit or lie down, and reward each with a treat. The dogs will become interested in the treats which will prevent the situation from escalating into aggression. Try letting the dogs interact again, but this time for a shorter time period and/or at a greater distance from each other.
Taking the Dogs Home: When the dogs seem to be tolerating each other without fearful or aggressive responses and the investigative greeting behaviors have tapered off, you can take them home. Whether you choose to take them in the same or different vehicles will depend on a few things; like their size, how well they ride in the car, how trouble-free the initial introduction has been and how many dogs are involved.
Once home: Do not leave the dogs alone, until you are confident they are getting along.
Introducing Puppies to Adult Dogs
Puppies usually pester adult dogs unmercifully. Before the age of four months, puppies may not recognize subtle body postures from adult dogs signaling that they’ve had enough. Well-socialized adult dogs with good temperaments may set limits with puppies with a growl or snarl. These behaviors are normal and should be allowed. Adult dogs that aren’t well socialized, or that have a history of fighting with other dogs, may attempt to set limits with more aggressive behaviors, such as biting, which could harm the puppy. For this reason, a puppy shouldn’t be left alone with an adult dog until you’re confident the puppy isn’t in any danger. Be sure to give the adult dog some quiet time away from the puppy, and perhaps some individual attention.