I fully get that in some cases, euthanasia of unadoptable pets is the only feasible option. However, I could never work at such a place. Too much misery. I already think of dogs and cats and horses as having individual characters and a full sense of awareness. This is very different than working with an aquarium full of Feeder Fish. All we can do is effect future births by spaying or neutering our pets early in their lives.
I agree. Inexpensive spaying is usually available, just getting people to have it done is a work in progress.