My sister's dog that they adopted from the shelter a few months back has recently started becoming very possessive of her and her boyfriend. If they try to pet any other dog while he's around he will immediately run over and bite the other dog. In the past week he has picked a fight with the boyfriend's parents dog after the boyfriend tried to pet the other male dog (at the boyfriend's parents house) and fought with my parents male dog just being outside with him (at my parents house not his own). He most recently drew blood on my parents 13 year old female lab. Do they need to consult a behavior specialist? Is there anything they can do?
