location, location, location---your region might make one's shelters prone to livestock, snakes, wild animals, etc. while another just has cats and dogs mostly
and more that people want to have chickens and ducks and other fowl in the city, you will see more and more of it.
also wild animals tamed, ferrets and all those varmints. boa constrictors, snakes, big lizards, etc. are all in shelters.
parrots and anything that can be a pet, shows up in shelters.