I kind of feel your pain. Lucky has major mood swings too. We brought her home from a Humane Society in February just before her second birthday. She frequently growls and bites at our feet, and she is just terrible when we are on the phone because she bites our hands and/or whatever else she can get her mouth on. She also sometimes bites us when we try to pet her. We're trying to break her of these behaviors. A shaker can or squirt bottle seems to work as a temporary solution, but she still continues these behaviors when we don't have a can or bottle near us.
I must say though, Lucky can be very warm and affectionate when she wants to be. Also, she does not seem to bite out of fear or viciousness. She typically growls and bites at our feet or hands when she wants some attention, exercise, or playtime. I think it could even be construed as an attack, but I know she is not trying to hurt us, because if I yell "Ouch!" and sound like I am hurt, she usually stops and looks at me. Sometimes I'll even get a little kiss as if she is saying "I'm sorry."
Anyways, I don't have any advice for you, but I wanted to let you know that your dog is not the only one that has some unexplained, seriously problematic behaviors. I'll be reading everyone's advice too. | 
08-16-2005, 10:54 AM
