Baby horses can go through fence corners when hit

What I expected to happen was...:
Fence blocking the movement of a hit horse

What actually happened was...:
When I hit a baby horse, it went through a fence

Steps to Reproduce:
1. Build a square of fences
2. Spawn a baby horse in it
3. Get the baby horse in a corner
4. Hit it (a few times)
5. The baby horse goes through the fence corner