In this article, we will discuss the causes of choke, how they are treated, which horses are predisposed to choke, and what can be done to prevent it. It is best to prevent choke, since the complications related with treating it can cause more problems for the horse. Causes Choke is the most common esophageal disorder in horses. Horses can become choked on many different substances, most commonly grain or hay, but also beet pulp, corn cobs, and apples. It's clear that overly large or bulky items won't make it down a horse's esophagus into the stomach.
Some feeds expand after they become moistened with saliva.
Pelleted feed and beet pulp expand quite a bit after getting wet. So, if a horse takes a large swallow of dry pellets or beet pulp and it mixes with saliva, it can expand enough to become lodged in the esophagus. This can also happen with hay. Horses can swallow large portions of hay not properly chewed first. The bolus of hay can then become lodged in the esophagus.