“It is work created by society but stigmatized by society,” said Rogelberg, who has studied the effects of the job on those who do it. “Society has created a need for euthanasia because they don’t adopt pets or spay and neuter them.” - Dr. Steven Rogelberg, a psychology professor at the University of North Carolina at Charlotte on 'A tormenting paradox"

This is the reality  - read A tormenting paradox (alt link).

If you have friends or family who have pets and won’t sterilise them, show this to them. (I got the link off this post). And tell them it’s not just unwanted pet animals who will have to die just because no one wants them - there are health issues for their unsterilised pets too, and (heaven forbid) the babies born, especially if they’re inbred, so STERILISE, dammit!