Havemeyer Report on Equine Gastric Ulcer Syndrome (EGUS)

The Dorothy Russel Havemeyer Foundation hosted a meeting on equine gastric ulcer syndrome (EGUS) in January 2025. Support was provided by that foundation and Boehringer Ingelheim. A final report was published and is available online. The title report was written by Benjamin Sykes, Gayle D. Hallowell, and Frank Andrews.

Following are some of the studies that were highlighted in the meeting summary.

Risk Factors for Treatment-Refractory EGGD

Dr. Gayle D. Hallowell noted in a 2024 online article that, “Equine glandular gastric disease (EGGD) is a separate entity from equine squamous gastric disease and is, until proven otherwise, a syndrome with different underlying causes.”

In 2015, the European College of Equine Internal Medicine (ECEIM) consensus statement made the distinction between disease of the squamous mucosa (equine squamous gastric disease or ESGD) and of the glandular mucosa (EGGD).

A research report presented at the Havemeyer meeting on EGGD was authored by Dr. Hallowell and colleagues. The meeting report stated that more than 3,000 cases of EGGD were examined between 2007-2024. Those cases were evaluated for the prevalence and risk factors of treatment-refractory disease in a sports and pleasure horse population.

Refractory was defined in two different ways, according to the authors. 1) Those horses that had not improved or worsened despite medication (one or more protocols) over a 3-month period. 2) Horses that had not healed with 3 months of treatment (same or different protocol but continuously treated).

Results showed that horses with no improvement or worsened was 8%, and refractory (not healed) horses was 38%. They also covered risk factors for refractory disease. Those risk factors included lameness, back pain, or were deemed ‘stressed’ by the owner or veterinarian.

Risk Factors for ESGD and EGGD in the U.S.

Dr. Hoyt Cheramie presented data on 1,433 gastroscopic examinations. They were performed between 2015 and 2020 and included a variety of breeds, disciplines, geography across the USA, and management strategies.

Client questionnaires concerning EGUS were taken and gastroscopic exams were conducted.

Overall EGUS prevalence was 86.3%. Cheramie found that 73.1% had squamous disease (ESGD) and 55.8% had glandular disease (EGGD). The report noted that 59.7% of horses with ESGD also had EGGD. Of that population, 30.4% had only ESGD and 10.8% of horses had only EGGD.

EGUS prevalence was highest in endurance (93.1%), cutting (90.3%), and western pleasure (90.2%) disciplines.

‘Bad’ attitude and ‘girthiness’ were the clinical signs most reported by the owner as being associated with the presence of both ESGD and EGGD.

The study’s findings suggest that EGUS remains a highly prevalent condition. Further, the primary presentation of behavioral manifestations of disease emphasizes the importance of EGUS to horse welfare.

Final Words

Additional research is needed for these conditions, summarized the attendees.

The group noted in its final report that, “It is also recognized that EGUS is not as visible as some other equine pathologies, such as fractures and exercise-associated sudden death. Without discounting the relevance of both conditions, the impact of EGUS on equine welfare and its relevance to social license and the ethical use of horses in sport should be considered, and further research into the condition is essential in the broader context of maintaining horse welfare and well-being.”