Although there is no way to guarantee that your dog will never bite someone, you can take these steps to significantly reduce the risk!
Spay or neuter your dog.
According to The Humane Society of the United States, spayed and neutered dogs are much less likely to bite. This routine procedure will also significantly reduce your dog's desire to roam and fight with other dogs.
Socialize your dog.
Introduce your dog to many different types or people and situations so that he or she is not nervous or frightened under normal social circumstances.
Train your dog.
Accompanying your dog to a training class is an excellent way to socialize him and to learn proper training techniques. Training your dog is a family matter. Every member of your household should learn the training techniques and participate in your dog's education.
Teach your dog how to behave.
Teach your dog appropriate behavior. Don't teach your dog to chase after or attach 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.
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 time alone in the backyard or tied to 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.