Interestingly there are grooms on board with the horses. They do everything a flight attendant does. Water sometimes hay, they have basic vet skills and help deal with any normal or emergency loading and offloading. Also to get the horses ear to pop on take off and landing they feed the horses carrots. They are the experts on board.

https://youtu.be/SdIW7wJCQc8

And instead of bringing you to indiana it brings you to india

I would probably be less annoyed by a plane full of horses than I am by a plane full of other humans