From the Academic Abolitionist Vegan blog:
"Euthanasia is an essential component to capitalism....
The arguments for euthanasia are really quite disturbing in this light, especially given similar projects designed to eliminate unwanted human populations that are a burden on the capitalist treadmill. I have heard it argued that not killing dogs and cats waiting on homes is “a waste of people’s time and money.” Ironically, I saw this argument made in an anti-capitalist animal rights space. But this is the very logic of capitalism, that is, to view sentient beings as disposable objects measured by their monetary value. Strange, when it comes to privileged groups, where there's a will, there's a way. When it comes to devalued groups, killing is just "common sense."
I also thought this was interesting, these debates chutning away in this corner of things:
"Classical Marxism is inherently speciesist and thus it should be the intellectual priority of socialist animalists to retheorize the position of non-humans within the system of thought. In classical Marxism, domesticated animals are literally reduced to machinery. So long as this is unchallenged, an anti-speciesist Marxism is impossible."