The prevalence and changes over time of equine glandular gastric disease in a teaching herd population

Background The natural progression of equine glandular gastric disease (EGGD) in the absence of treatment has not yet been described in the literature, nor has the prevalence in a teaching herd population been reported.Objectives The aims of this study were to determine the prevalence of disease in a teaching population over the study period (2019-2021) and to observe the changes over time in disease severity of naturally occurring diseases (not experimentally induced) without medical intervention.Methods Twenty-one horses underwent an initial gastroscopy and a repeat gastroscopy between 14 and 731 days later. Gastroscopy data were graded quantitatively and described qualitatively. Prevalence and 95% confidence intervals (CI) were calculated. The changes over time were determined by comparing initial and repeat gastroscopies.Results The prevalence from initial, repeat and total number of gastroscopies was 62% (95% CI: 40.8-79.3), 71% (95% CI: 50.0-86.2) and 67% (95% CI: 51.6-79), respectively. The changes over time included worsening of disease in 29% of horses (95% CI: 13.8-50.0), improvement of disease to a lower grade in 24% (95% CI: 10.6-45.1), no change in grade in 38% (95% CI: 20.8-59.1), and complete resolution of disease to grade 0 in 10% (95% CI: 2.7-28.9).Main limitations Limitations included a maximum of two gastroscopies per horse given COVID-19 restrictions on data collection, and highly varied interval times between initial and repeat gastroscopies.Conclusion In conclusion, there is a high prevalence of disease in this teaching herd. The changes over time in naturally occurring diseases without medical intervention might include worsening, improvement, no change or resolution of disease.