Get Professional Help ASAP!
If your dog has bitten a person or another dog with enough force that they punctured the victim's skin, it means your dog did not learn reliable bite inhibition as a puppy, so there is a good chance they may hurt another person or dog in the future.
I'm sorry to have to say this but your dog is dangerous and now that you know that your dog is dangerous, you have a responsibility to manage your dog's access to people and other dogs in such a way that you can ensure your dog will not injure anyone else, especially children.
Unfortunately, teaching reliable bite inhibition to an adolescent or adult dog is extremely difficult and time-consuming and not without danger and so, you need to immediately find a skilled professional dog trainer who can evaluate your dog and help you determine the best course of action. Until then, please confine your dog safely at home.
To find a Certified Dog Trainer in your area, please consult the trainer-search databases of The International Association of Animal Behavior Consultants, or The Certification Council for Professional Dog Trainers. Both of these organizations have standards and accreditation requirements for all of their members.
Look for a trainer who has experience with aggression using reward-based techniques such as classical conditioning and progressive desensitization.
Remember, most reactivity stems from lack of socialization and experience and as such, is fear-based. Excessive punishment may make reactivity and aggression worse – giving the dog two reasons to be upset – fear of people or dogs AND fear of the punishment, especially if that punishment is painful or very unpleasant. Yes, you need to learn how to control your dog's behavior but most importantly, you want to build your dog's confidence to enjoy the company of people and other dogs.
Every new and prospective puppy owner needs to understand how to teach bite inhibition and how to socialize their new puppy during puppyhood. It's easy, it's fun, and it's incredibly effective at ensuring that their pups will have the confidence to enjoy living around people and when they grow into adult dogs, they will not be a danger to others.
Your dog can have terrible manners, zero obedience, and a whole slew of frustrating behavior problems, but so long as they have reliable bite inhibition, we can help you safely train your dog. But if your dog has ever caused a serious injury to a person or another dog, you need professional, one-on-one help right away.
So please, please, please help us spread the word about teaching bite inhibition to puppies by telling all of your family and dog-loving friends about our free course collection and the Dog Lover's Library here at DunbarAcademy.com