I also heard about this. It's probably a mutation, but Parvo is an extremely deadly disease and it's hard and expensive- for a dog to bounce back from if they become infected. Poor pups, but probably extremely fucking stupid people. There are such things as affordable (sometimes traveling) vaccination clinics if you don't have the money. Dogs that are seized or abandoned at shelters are highly susceptible and shelters are severely undefunded and can only do so much.