In introducing a new dog to a pack, the first step is to examine and assess the dogs currently in your pack. All dogs are unique animals, and some dogs are more amenable to being with new dogs. However, there are some general rules: Same sex pairs don't get along as well as opposite sex pairs. Dominant dogs don't get along well with dominant dogs. Dogs that have a high prey drive, for example, dogs that love to chase squirrels or other small creatures, will get along better with adult dogs. Here's how to successfully introduce other dogs to your pack.
- Introduce the dogs to each other in a neutral location, but don't assume that dogs will get along just because you want them to; dogs need to get to know each other before you can expect them to live together as a pack. Dogs don't need to meet in the same way humans do, you don't need to arrange a meal together, in fact, when introducing a new dog to the pack, and meal time is the worst time to introduce a new dog. Instead, take the other members of the pack and the new dog, and go on a long but casual walk. Give all the dogs the opportunity to get to know the new animal in a positive situation where you are reinforcing your position as the alpha member of the pack. Never forget that you are the leader of pack, and be ready to separate the dogs if there is any sign of fighting.
- Continue the slow introduction of the dogs at your home, keeping the leash on the dogs while you let them play in your yard, keeping the dogs under close supervision and for short increments of time, say, ten minutes at a go. If the dogs look like they are having fun and playing nice, you can slowly let the dogs off of the leash. This process can take some time, from one week to many weeks.
- Follow a similar process when feeding the dogs. Start off feeding the dogs separately, and then slowly move them closer and closer until they are eating at the same time in the same room.
Three months is the honeymoon period with a new dog. The dog will be on its best behavior during this time period, and it's entirely possible to see aberrant behavior develop after that time period, even as far as six or nine months from the time a new dog comes to live with your pack.