Why can't horses throw up?

Horses are unable to throw up primarily because of their unique digestive system. Their anatomy is specifically designed for a continuous grazing lifestyle, which means they have a one-way digestive tract that is efficient for processing fibrous forage. The entrance to their stomach is equipped with a strong valve that prevents the backflow of nutrients, making regurgitation impossible. This adaptation is beneficial for horses, as it ensures that food passes through their system smoothly while minimizing the risk of choking or aspiration.

While there may be other factors related to how horses eat or their instincts, these are not the primary reasons behind their inability to vomit. Their digestive process is the key aspect that differentiates them from some other animals that do regurgitate food.