Arizona is one of the weirdest states I have ever heard of. It depends on whether you live in a township or county....and if in a township, it depends where in town you live. In my town, it was just changed from 3 to 2 horses per acre. In these areas, other livestock is not allowed. Luckily my parents property is slightly over 1 acre so we are grandfathered for the 3 and the overage covers us technically for the 4.
But there are areas where the sky is the limit, and you can have anything on four legs or with feathers. I pass by a horrible house every trip to my barn....and they have many horses, cows, steer & sheep crowded into tiny pens where all they can do is stand or lay. I have already called the livestock inspector, and she is aware of this location, but so far they aren't doing anything wrong....and she does keep tabs on them. Oh and even with 115-120 degree searing sun during the summer, NO shelter is required. An awful lot of animal suffer down here in the "old west"