aggressive American bulldog

I have not used a head collar as he is wonderful to walk. When I walk him in a group of dogs I use a pinch collar that was recommended by the trainer because as with most dogs he forgets how to heal when he is with his buddies.
When he is aggressive I usually jerk on the leash and put him in a down stay. He will lay there no problem but if the person moves in any direction or evn their hands he will jump back up and try to get them again. He does not try to get people when I am walking him only when in the house or if a stranger approuches him to pet him. If someone just walks past him he ignores them. I have also tried giving him time out. Then bring him back.If he does it again he gets another one. Anyone who comes to the house is not allowed to touch him or make I contact. They don't usually speak to him either. They are usually to afraid.When I leash him before someone comes over I do a quick sit stay come down before they get there but when they come in he still looses it. So I have started putting him away allowing them to sit down then bring him out. He will lay beside me but like I said any movement and he could go nuts. I have a feild by my house so sometimes when he is with Uno (dogo mastiff) we will let them off leash. If someone sneaks up on us. He runs righ tover to them and does nothing. But I am afriad that could change. He seems to like people that have dogs with them. I try not to be nervous so he wont get any bad feelings from me but when he tries to eat someone it is very scary.

Hi again gibson sorry for the late re-reply. I have given your situation considerable thought. I think at this point as catecate says, you need to consider visiting a behaviourist in you area to work with you and your dog personally to get this situation under control without anyone being put at risk. When a dog is regularly biting other people training to reverse this situation needs to be very intensive and you will need constant observation, support and feed back in order to be effective. In the mean time I would also recommend switching from a pinch collar to a head collar for increased control, the ability to close the dogs mouth and to help prevent lunging and snapping. Most importantly pinch collars promote aggression in already aggressive dogs as does any form of physical correction and can increase the dogs negative associations with meeting strange people and dogs. Also if you feel anyone is in danger use a muzzle for full protection.

I am sure you will soon find a good behaviorist in your area who uses effective positive reinforcement methods and you and your dog will soon be having a much easier time with visiting and meeting people. Please let us know how you get on.