All states have statutes that pertain to dangerous dogs, and most states allow counties and cities to enact local laws that govern dogs and their owners. There are literally three sets of laws that govern dangerous dogs in many places. For example, California has a dangerous dog law, Los Angeles County has its own, and the City of Los Angeles has another.
From city to city, these laws are not uniform. For example, in some places it is illegal for a dog to attack another dog, while in others it is not. In September 2004, a pit bull on a busy Manhatten street bit off the head of a Chihuahua, and the animal control authorities correctly announced that there was nothing they could do; New York was one of the states that did not make it illegal for a dog to maul another dog (until after that incident was publicized).
The dangerous dog laws are enforced in proceedings that some refer to as “dog court.” These hearings, like the laws they apply, are far from uniform from county to county, state to state. The hearing officers are sometimes experienced lawyers, but at other times are animal control officers with no legal training. The victim might or might not have the right to counsel. The legal issues depend on the state’s concept of due process, and the city or county’s dangerous dog ordinance, leash law, running at large law, trespass law, and possibly other laws; there is no uniformity. The prosecutor might be the victim, the victim’s lawyer, an animal control officer, or a city attorney. The consequences might or might not include a fine, a prohibition against owning dogs in the future, euthenasia, signage around the house, keeping the dog in a cage, muzzling it in public, tatooing it, or a number of other things.