This law should ALSO REQUIRE the owners to take their pets and that would FORCE RESPONSIBILITY on those who normally try to evade it.Likewise,those who ignore this law and their pets are rescued should be heavily fined and billed for food,housing and medical care.
I guess you posted the key word here: RESPONSIBILITY, individual responsibility, that is. Not Daddy Government's responsibility!
Now see you have a plan, at least it is an idea. I don't see why it has to be just leave all the animals to die