Using Nutrition to Manage and Prevent Stomach Ulcers in Horses

Introduction
Stomach or gastric ulcers are a common concern for equine caretakers. Stomach ulcers occur when the stomach lining is damaged by stomach acid. While stomach ulcers are most common in racehorses all horses can potentially suffer from ulcers including horses that are in light exercise or rarely exercised. Nutritional management is a key piece of the puzzle when managing ulcers. Several feed management practices can be put into place to help horse owners better manage their horses ulcers and decrease the risk of future ulcer development.

Gastrointestinal Ulcers
Equine Squamous Gastric Disease ESGD is a specific type of ulceration that can occur in a horses stomach. Ulcers can also occur in the glandular portion of the stomach and in the hindgut however these types of ulcers have different causes treatments and management recommendations and will not be discussed in this article. Clinical signs of ESGD include poor body condition weight loss clenchinggrinding of teeth and colic. Some horses may even display changes in eating habits and behavior such as decreased appetite and sensitivity in the back or girth area.
Ulcers can also affect a horses overall performance with horses suffering from ESGD underperforming in competitions. Equine Squamous Gastric Disease is common and is diagnosed in 1190 of adult horses depending on which population of horses is studied. Ulcers are more common in horses that partake in heavy exercise such as racehorses and Olympic level competitors with a prevalence rate ranging between 90100. While ulceration rates are lower ulcers have also been found in 1159 of pleasure horses which are not considered to be in heavy exercise. This highlights the potential welfare concerns for horses with ESGD and implies how this could have an economic impact due to underperformance of the equine athlete and cost associated with treatment.
Stomach Anatomy
In order to explain how stomach

ulcers can develop lets first talk about equine stomach anatomy Figure 1. The horses stomach is an essential step in feed digestion ensuring that nutrients can later on be absorbed in the intestines. In order to begin the breakdown of feed before it exits to the duodenum the stomach secretes acid from the glandular lower portion of the stomach. The cells present in the glandular portion are different from the cells that line the upper portion of the stomach. The acidsecreting cells in the glandular portion of the stomach also secrete mucous creating a layer to protect the cells from the acidic stomach environment. In contrast in the upper portion of the stomach known as the squamous or nonglandular portion of the stomach
known as the squamous or nonglandular portion of the stomach cells do not secrete stomach acid or mucous. Because the squamous portion of the stomach does not produce a mucous protectant it is susceptible to acid damage. Dividing the glandular and squamous sections of the stomach is a structure called the margo plicatus. The margo plicatus is a visible line that marks where the stomach lining changes from the squamous  to the glandular portion. Most often ulcers develop in the squamous portion of the stomach along the margo plicatus. 
Acid Damage and Ulcer Development
Since the upper squamous portion of the stomach does not secrete mucous to protect itself from stomach acid acid damage can occur leading to ulceration known as ESGD. Unlike humans who only secrete stomach acid when a meal is ingested horses continuously secrete stomach acid throughout the day. Saliva contains an important buffer bicarbonate which helps to neutralize the stomach acid but this is only secreted in a healthy horse while they are chewing. For example if a horse is only fed twice a day then they may run out of forage in