I've had 2 humane society dogs with wonderful results. The first was a black lab. Everybody knows what they are like. My son cut his teeth on her tail, and used her for a mobile support system when he was learning to walk. The second was a Terrier mix, definitely more of a gamble regarding possible behavior issues. she was returned at the age of 4.5 months because of "allergies". Yeah right! Her info tag said she was house broke. Yeah right! It was obvious that she was not house broke, she had never experienced stairs, and her behavior also told me that she had been abused by children and a large man. But, with work and love, she turned into a wonderful pooch who was loved by everybody who met her. She was extremely smart, considered it her job to "herd" the kids, keep babies from crying, mother baby kittens,and keep tabs on everybody. She played hide and seek, taking turns (hiding and seeking) with the 2 legged participants. Personally, if i was getting an other dog, I'd definitely look for an other pound pup. IMO, most dogs have behavior issues because their people don't know how to train a dog, or don't give it enough attention. I've seen plenty of "pure breds" with health issues and behavior problems. Dogs are like a box of chocolates: you never know what you're going to get! But, if you spend some time with the dog, observing (from a distance) it with other dogs, and then getting more personal with it, you're apt to make an informed decision.