And in response to your last message, putting humans over animals is speciesism: no animal (human or non-human) life is worth more than another.
I don’t have any evidence for the selective breeding comment which is why I only suspect it. I think this because other institutions that use animals (e.g. Guide dogs for the blind) use selective breeding.
1. Because animals are not for humans to use. Especially if the animals are at risk from harm.
2. Police officers and police horses face dangerous and scary situations, however the police officers chose that job, the horses didn’t.
3. Police horses are often targetted by rioters.
4. Police horses only have some body protection so they are still at risk from significant harm.
5. Horses can scare easily and innocent members of the public have been hurt due to charging police horses.
6. I suspect there’s some sort of selective breeding that goes on behind the scenes which generally means abuse and death.