Arizona has a specific law that states the liability for dog owners (ARS 11-1025).

The owner of a dog which bites a person when the person is in or on a public place or lawfully in or on a private place, including the property of the owner of the dog, is responsible for damages suffered by the person bitten, regardless of the dog's viciousness in the past or the owner's knowledge of its viciousness.

This law does not apply to any governmental agency using a dog in military or police work if the bite occurred while the dog was defending itself from a harassing or provoking act, or assisting an employee of the agency in normal work duties.

If you wish to sue, file the claim in court within one year from the date of the attack.  You may want to contact a lawyer to determine your rights and assist you with filing a claim.