Try leaving music on for him when you go out.. just the sound of noise might help him calm down. Right before you go out the door... if he isnt in a kennel give him a toy with some peanut butter smeared on it.. put it in a room that he wont be able to see you leaving from. sneak out while he is busy... this may work... and just stand outside the door to listen. maybe for 10 mins and then come back in.. get him used to knowing when you leave you will come back.
I would really reccomend crate training.. then when you leave you can just put a blanket over his kennel turn on the music and sneak out the door..
biting his leash.. practice in the house when he does bite it hold the leash with two hands about a foot apart and push it into his mouth while he is biting it and say no. I saw this on a dog training show.. so more or less it will be pushing against the back of his mouth. hard to explain..
Anyway theres a few suggestions.
Also have you done basic obedience.. it might be a good idea especially since it sounds like this is your first pitbull... dont let him get out of hand and dont take his sh*it lol!
Proud mum of Mr. Big. (Lab)
Mr. Big- 11 months old
Soon to be proud mum of Gilgamesh.
(Olde English Bulldogge)
*Lab Lover [COLOR=red]<3[/COLOR]