I always say: If I can't think of a reason it's wrong other than "god said so", then it's not really wrong.
In this case, animals can't give consent. Probably doesn't hurt them emotionally or physically, but it's still abuse. That'd be like saying you can rape a mentally handicapped person who doesn't have the capacity to understand.
In this case, animals can't give consent. Probably doesn't hurt them emotionally or physically, but it's still abuse. That'd be like saying you can rape a mentally handicapped person who doesn't have the capacity to understand.