They have a massive problem with Rabies, so some idiot came up with the idea of limiting pet ownership, although as you would expect the majority of cases are in the stray population, this has led to even more dogs being left to roam the streets as pet owners are forced to abandon their pets increasing the Rabies problem!
It doesn't help that pet dogs were a status symbol and the government practically encouraged ownership to reduce the stress/trauma of the 1 child rule so many pet dog owners have multiple pets.