HOW TO STOP A DOG FROM BITING OFF VICTIM'S...
Despite a lot of legends telling the stories about some dogs having a locking mechanism in their jaws, these legends are only myths. This legendary Pitbull simply have the determination of a terrier. Sometimes extreme situations will require from you more risky methods to break the dog's bite.
Break release command, pulling on the leash, pouring water on your dog's face or picking a very determined dog up by his hindquarters will simply not work. Even break stick method can fail when things start getting pretty hot.
Although I believe in using the safest possible methods of handling dogs, sometimes choking method might mean the only way to release determined dog's grip. Grabbing the dog's collar in this situation can be very risky method not only because of close proximity to dog's teeth, but you can also damage the dog’s trachea or kill the dog if you use more force than intended.
So remember!!! Be responsible dog owner and get some training for yourself and your dog. Breaking up dogs fights is a risky business. The only thing that can make the prospect safer for you is knowing a little bit about judging when and how to intervene.
Here's a video of Shmulik B. a professional dog trainer and an AKBAN academy veteran on how to stop an attacking dog assault from biting a victim in one of those extreme situations.