Horses not breathing while running opened a whole new world of anxiety for me.

imagine having a stuffy nose and you can't breathe with your mouth.

I always thought the fact that turning our heads too fast can give us strokes was rather inconvenient.

the lack of a highly clickable abstract and title that ignores the last names of many of the people involved leads me to believe this is a satire

Horses were at least marginally less ridiculous before people got involved. Not quite to the same extent as dogs, but compare a steppe horse with a thoroughbred and you'll see that they're smaller and hardier. Much better equipped to live, slightly less able to carry fully armored people on their back.