At what level of an enemy will a horse run away instead of attacking?

Question

I have noticed that horses will attack some less-strong enemies but will run away from other enemies, especially dragons.

What level does an enemy have to be in order for a horse to run away instead of attacking?

Answer 1

It's all depends on the enemy level. Normal horse including Frost is a level 4 creature so it will attack any enemy below level 4. Exception for Shadowmere, it will attack any enemy insight (including dragons) because it is a badass level 50 horse.