Hi, I am new to blogging on the 'zine, although I have been a reader for some time. My question pertains to my 16-month-old rescue pup, Gizmo, whom I obtained through the local shelter last December. He was listed as an "owner release", supposedly because the owners were moving to a place where they could not have pets, but given some of his proclivities I am beginning to wonder. For starters, Gizmo hates tall women. At first it was just tall women over forty, but now he attacks and tries to bite any tall woman or girl he sees (over 5'5"). He also has a problem with males that exhibit aggression or who try to dominate him, any age. He has gotten to the point where he gets along with my boys (ages 12, 11, & 9) no matter how they act, but all my 16-year-old brother has to do is enter the room too aggressively and Giz goes after him. The more aggressive stance a person takes in response, the worse Gizmo gets and the more likely he is to escalate from growling and snapping to biting. Short women and girls usually have no problems with Giz, unless they exhibit fear and dance around or run from him. I am 5'2" and so is my daughter; we have no trouble with him at all. Recently, however, he has gone after two of my (short) sisters when they tried to pet him- they have never had problems with him in the past. He also tried to bite my 85-year-old grandmother and my 50-year-old aunt- both are tall women and both are dog people. He was fine with my aunt at first, as he met her when she was in a reclining chair, but when he later saw her walking through the house, he started barking and growling at her. My grandmother was sitting in a rocking chair when I brought Giz in to meet them and he disliked her from the first and kept jumping up on her legs and snapping at her hands and would not leave her alone. I had to tie him up outside for the rest of the visit. However our counselor, who is 5'7" and over 50, and visits our home twice a week for sessions had problems with him for several weeks after I got him, but then he acclimatized to her (she is a dog lover and really worked with him). I am at my wits end to know what to do: I have tried using a "Friend" command, I have tried having visitors give him a treat (he will take the treat and then snap at them if they try to pet him), I try to always keep him leashed when outside, but occasionally he sneaks out the door anyway and attacks people walking or biking on the street. Any ideas or help would be appreciated. I'm thinking of buying a muzzle for when we go out in public or to visit. Thanks, Robin