People don't have to dehumanise animals to slaughter them.
American Indians thanked the spirit of the animal that just killed. Kobe husbandsmen massage, wine and dine their prized cattle. A guy in a Reader's Digest joke was surprised his daughter was delighted the cow with big blue eyes she fed through the fence ended up on her plate.
Greek-Roman traditions allowed a soul to animals. Humans have a God-given part that allow them to determine right and wrong for themselves. This passage by Marcus Aurelius, Roman emperor upto 180 AD and Stoic philosopher assumes it.
> The mind is the ruler of the soul. It should remainunstirred by agitations of the flesh—gentle and violent onesalike. Not mingling with them, but fencing itself off and keeping those feelings in their place. When they make theirway into your thoughts, through the sympathetic link betweenmind and body, don’t try to resist the sensation. Thesensation is natural. But don’t let the mind start in withjudgments, calling it “good” or “bad.”