> You can pen a horse by painting stripes on the ground around it.

No way. Horses are quite good at evaluating ground obstacles. I've never had a horse hesitate at a painted line.

There are some breeds of cattle which will not cross a painted imitation of a cattle guard, but those are beef animals bred to be dumb and docile.

We know it’s specifically a fear of deep water because there is visible different behavior when dogs run on strange but solid surfaces and water in general like puddles or hosing a dog with water.