In the second part of the 3 part series focusing on EGUS (Equine Gastric Ulcer Syndrome), the authors looked more closely at ulceration of the squamous portion of the stomach (Equine Squamous Gastric Ulcer Syndrome – ESGUS). They reminded us that horses are constant gastric acid secreters and that the roughly basketball-sized bolus of feed (mostly roughage) in the stomach acts as a buffer to absorb gastric acidity. The prevalence of ESGUS “mirrors exercise intensity with the risk of disease increasing as the intensity of work increases”. The authors also stress that while the prevalence of ESGUS is much lower in horses at rest, severe gastric ulcers were detected in this group and that 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 then becomes logical to believe that removing/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 has 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 is similar to treatment, 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.