Just to clarify; when I say 'Kill a dog' I am referring to vet-assisted euthanasia. There is no reason someone can't take a dog or cat in to a shelter where it would be euthanized for free, as there aren't restrictions on who will even see them like there are for reptiles, and the euthanasia process has been proven to be humane for them.
(And I am also talking about severely ill strays that would have endangered my other animals and been an impossible financial burden. They were never taken in with the instructions to euthanize; but they were given to shelters that almost immediately had to do just that).