Horses are constant gastric acid secreters, and the roughly basketball-sized bolus of feed (mostly roughage) in the stomach acts as a buffer to absorb gastric acidity. The prevalence of Equine Squamous Gastric Ulcer Syndrome (ESGUS) mirrors exercise intensity with the risk of disease increasing as the intensity of work increases. While the prevalence of ESGUS is much lower in horses at rest, severe gastric ulcers were detected in horses not in work and ESGUS should be considered in the differential diagnosis (list of possible conditions that fit a set of symptoms) even in a horse that does not fit the “typical profile”.
Management plays a part in ESGUS, especially the changes that can occur when a horse enters training, including factors such as exercise, high concentrate/low roughage diets, fasting, transport, stall confinement, administration of “hypertonic electrolytes”, and intermittent access to water. It is logical to believe that removing or reducing the impact of those risk factors will help to reduce the incidence of gastric ulcers.
Treatment of ESGUS focuses on suppressing gastric acid production, and a variety of drugs have been used for this purpose, omeprazole (Gastrogard®) being the one most studied to date. A small number of horses with ESGUS do not respond well to treatment with omeprazole, such that other therapies need to be considered.
Prevention of ESGUS involves removing as many of the risk factors as possible and approaching each horse as an individual when determining therapy. If the reduction of risk factors is not possible, then the risk of recurrence of ESGUS is high, and the horse should be treated accordingly.
Scientific Review Article: Sykes, BW and Jokisalo, JM. “Rethinking equine gastric ulcer syndrome: Part 2 – Equine squamous gastric ulcer syndrome (ESGUS) ”, Eq Vet Ed, May 2015, pp. 264-268.