No, not a denizen of Equestria. Horses in fiction tend to be impossibly cool already. They can gallop for miles on end without any sign of fatigue. And sometimes they require minimum care, or handled in ways that are downright unsafe without any ill effects. This trope can also extend into fallacies regarding equine biology. For instance, if you ever see a horse gagging in a cartoon, it falls into this trope. Horses in real life cannot vomit, which can lead to deadly bouts of colic should they eat rotten, moldy, or even excessive quantities of food.