Many years ago the term of choice when killing laboratory animal at the end of a study was "sacrifice". It was a word choice that got dropped not only for being euphemistic but also just ridiculous; conjuring up images of robed men and chanting as the rats were laid on top of the granite altar of some kind.
But the word has reappeared strangely in some reports of apparent murderer Vester Lee Flanagan's previous killing of his pet cats.
"There were arguments and confrontations at work, periodic eruptions,
including a road rage episode captured on video and a sacrifice of his
two pet cats, killings that Mr. Flanagan said he carried out because of
anger at his firing."
At least in the case of scientific research there is some amorphous idea of what the animals' lives have been sacrificed to or for. But in the case of violent, rage-fueled animal abuse, I struggle to see how this word applies at all.