We have two Vizslas, 3 years old, brothers, same litter. They have always been so close and play together very good. They hate being separated from each other. About 3 months ago they have had bouts of fighting each other and I mean FIGHTING!! They draw blood, injure each other and act as if they want to kill each other. The only way we got them separated was to eventually pull them apart, which was a huge struggle. We have to hold them to calm them down, tend to their wounds, then separate them in their own crates. We had them neutered after their first 2 fights hoping that would take care of the problem. They had a 3rd fight approx. a month after being neutered. Now we keep their shock collars on at the highest setting and will use that if and when they fight again. We love them both and do not want to get rid of one. Has anyone had this issue or have any suggestions? Is there any type of training we can send them to for this? HELP!!!