Dogs bite for many reasons. Remember that they are animals and a bite is a form of communication. Dogs may bite out of fear or pain. A mother dog with very young pups might bite out of the maternal instinct to protect her babies. Dogs can also bite if they have been pestered too much - it's their way of saying no.
There is no way to guarantee a dog won't bite, but you can significantly reduce the risk. Spay or neuter your dog. It can reduce the desire to roam and fight. Properly train your dog. Take him to obedience training where positive reinforcement (rewards, not punishment) is used. Teach him how to walk on a leash. Socialize your dog so he is used to different experiences.
Teach your children how to interact safely with dogs. Most dogs don't like hugs and kisses. Face-to-face contact is one of the most common causes of bites to the face. Encourage children to scratch the dog on the chest or side of neck. If a strange dog approaches, teach your child to stay still. This also works if the family dog gets too frisky and aggressive. As a parent, you need to supervise your children when they are interacting with dogs. Pet and touch dogs together. Spend family time together so the dog can get used to your younger children.
For more information on dog bite prevention or spaying and neutering, call (602) 506-PETS (7387) or visit www.pets.maricopa.gov.