Other suggestions from the Humane Society of the United States on how to prevent your dog from biting.
Teach your dog how to behave
Teach your dog appropriate behavior. Don't teach your dog to chase after or attack others, even in fun. Your dog can't always understand the difference between play and real-life situations.
Set appropriate limits for your dog's behavior. Don't wait for an accident. The first time he exhibits dangerous behavior toward any person, seek professional help from your veterinarian, an animal behaviorist, or a qualified dog trainer.
Your community animal care and control agency or humane society may also offer helpful services. Dangerous behavior toward other animals may eventually lead to dangerous behavior toward people, and is also a reason to seek professional help.
Be a responsible dog owner
License your dog as required by law and provide regular veterinary care, including rabies vaccinations. For everyone's safety, don't allow your dog to roam alone. Make your dog a member of your family: Dogs who spend a great deal of time alone in the backyard or tied on a chain often become dangerous. Dogs who are well-socialized and supervised are much less likely to bite.
Keep your dog away from stressful situations
If you don't know how your dog will react to a new situation, be cautious. If your dog may panic in crowds, leave him at home. If your dog overreacts to visitors or delivery or service personnel, keep him in another room. Work with professionals to help your dog become accustomed to these and other situations. Until you are confident of his behavior, however, avoid stressful settings.