Today it’s the armadillo I. Believe that carries animal leprosy? Not sure but I think opposums might carry so ethi g too?
Like smallpox, it must have a non-human reservoir to keep coming back, so, probably a number of different critters are at least capable of it. Used to be the armadillo was the only known animal host, but armadillos weren't around in the Biblical Middle East, and I'm not sure squirrels have ever thrived there, so, probably some other rodent (gerbils, hamsters, rats, mice) or rodents (all of them?) keep it around.