The aim of this study was to determine the prevalence and association of EGUS in horses of different ages, breeds and occupations. Gastroscopies were performed on 395 horses, and gastric ulcers were graded on a scoring system from 0 to 4. The relationship between age, breed, and work, along with the prevalence of gastric ulcers and their influences, were evaluated. The prevalence rate of ulcers in this herd was 78%. Older horses were prone to ulcers in both the glandular and squamous mucosal areas. Across the different jobs surveyed, 60% of the horses had a score of 2 or above. For the horses participating in more intense jobs (group performances, pulling carts, etc.), the number of horses with an ulcer score of 2 or above exceeded 50% of the total number of horses in this job. The prevalence of gastric ulcers was high, and these ulcers were severe in the horses belonging to the examined club, with no association between age or breed and the prevalence of ulcers; however, there was a difference in the location of the ulcers between breeds, as well as differences in the incidence and severity of ulcers depending on work activity. This study provides data reference values for the control and prevention of gastric ulcers in horses in this horse farm.