Many donkeys are used to protect sheep and goat herds from predators while others are kept as pets.  A donkey’s stomach is the same as a horse’s.  Stomach ulcers are a common problem in horses, especially performance horses. The stomach has two parts, the glandular and non-glandular portions.  In horses, the most common cause of ulcers on the non-glandular potion is exercise because as the horse moves the stomach acid splashes up on the unprotected portion.  However, since donkeys don’t usually do a lot of rigorous exercising, it is surprising that donkeys can also develop stomach ulcers in the non-glandular portion of their stomachs. 

An Italian study was conducted on 39 donkeys. All of these were non-athletes and non-working donkeys.  All underwent stomach exams with a gastroscope. None were on any medications. Results were that 51% of the donkeys had stomach ulcers and 95% of those were in the non-glandular portion.  It was really surprising that this many non-exercising, non-working donkeys had ulcers, and that the ulcers were in this area. 

For horses, other reasons for ulcers in this area include high-carbohydrate rations and being stalled and fed intermittently.  Most donkeys are not routinely stalled and are out on pasture grazing, which generally decreases the chance of ulcers.  Also, most donkeys are not fed - and should not be fed – high-carbohydrate rations so the reason for the stomach ulcers is unknown at this time.  However, it is important to know that over half of the donkeys in this study had stomach ulcers and this could be a reason for decreased appetite or colic in donkeys.