I have a 3-year-old American Straffordshire Terrier and she is above and beyond the most loyal and loving dog I have ever owned. I take her everywhere I go and she is great with my 3 children. My problem is that I have gone to local shelters to find her a companion of the same breed but she gets jealous and wants to fight the other dog. Any suggestions?
I suggest you tune into the Dog Whisperer with Cesar Millan on the National Geographic Channel (if you have not done so already). He shows over and over again how to get two dogs to get along. He deals with a lot of powerful breeds. What you do not want to do is just toss the dogs together face-to-face at the first meeting in a shelter environment where the dog you are adopting is most likely lacking in exercise and human discipline. Before you even consider a second dog you need to first master the walk with your first dog.
On the day of adoption take your first dog for a really long walk or jog so her energy is drained before she meets this second dog.
As for the second dog, that dog needs to be taken for a walk as well to drain her energy. Then you would have a second person with you at the time the dogs meet and pack walk the dogs at the same time. Do not just stick them face to face. Just walk and walk for a long time. Both dogs need to be heeling because if one dog is allowed to be in front that dog will instinctually feel he is the leader of the bunch and will try and dominate the pack. Correct any negative reactions the dogs may have towards one another. While walking you can allow the dogs to smell one another's rear ends if the dogs are acting civil. By the end of your walk the dogs will regard themselves as one pack and if the humans were successful in convincing the dogs the humans are the leaders, the dogs will not feel the need to dominate or be leader. You will need to find a shelter that is willing to work with you on that method. Unfortunately too many shelters do not understand this concept and a lot of dogs are put down because of it.
I highly recommend you watch a good number of the Dog Whisperer shows before proceeding so you fully understand the basis behind this method.