[astrange]

Horses aren’t workers, they’re horses. They didn’t ask to participate in the economy in the first place.

[_dain_]

Nobody asked me whether I wanted to participate in the economy either, yet here I am.

[trention]

The affirmative answer to that ask was implicit in the first employment contract you signed. So, unless you'd claim that horses can give implicit consent by accepting grain from a human, the equivalency fails.