http://www.tennessean.com/article/20100220/OPINION03/2200317/1008/OPINION01/Neutering+pets+improves+the+quality+of+their+lives

Also, neutering has a direct impact on the incidence of dog bites in a community. The majority of dog bites (60-80 percent) are caused by intact male dogs. Pregnant or nursing female dogs are more likely to bite, as well. Reducing your pet's likelihood of biting or fighting may also help protect you from potential legal action.