Fake Horses..

Why a film might use these:
1. They aren’t unpredictable, so they’re much safer.
2. Not needing to pay for and use animal rules and regulations.
3. You don’t need to feed or pay the animal actors.
4. They don’t get tired, injured, or sick.
5. Actors can focus on acting and not focus on what the animal is doing.
6. Actors with allergies won’t need a doctor to manage said allergies.
7. You won’t need to pay for a vet and stable.
8. No need for a trainer.
9. Actors don’t need riding lessons.
10. The production aren’t restricted to filming a maximum amount of hours with them. (Animals have strict laws surrounding them.)

The list is very extensive..