Arizona's real strict liability statute
Under A.R.S. §11-1025, a dog owner is strictly liable when their dog bites someone who is in a public place, or lawfully present on private property (including the owner's own property, as defined in A.R.S. §11-1026). You don't need to prove the owner knew the dog had ever bitten before — this ended Arizona's older "one-bite rule" for bite injuries specifically.
A separate statute, A.R.S. §11-1020, covers a dog "at large" (off-leash or unconfined) that causes injury or property damage — and unlike §11-1025, this covers non-bite injuries too, like being knocked down, and applies to both owners and other responsible possessors.
The owner's main defense is provocation, under A.R.S. §11-1027. Arizona's strict liability statute applies only to bites specifically (not scratches or knockdowns), and only to the dog's owner, not other possessors like a dog-sitter or landlord, per Arizona case law.