Demographics and health of U.S. senior horses used in competitions.

Background: A proportion of senior horses (≥15 years of age) are still used for competition. Information about this particular group of horses is currently sparse.

Objectives: To provide an overview of the demographics, management and health of competing U.S. senior horses (≥15 years of age).

Study Design: Online survey.

Methods: Descriptive and inferential (Kruskal-Wallis test) analysis of 246 surveys from owners of U.S.-resident senior horses used for competition. Confidence intervals were calculated for prevalence estimates of clinical signs and medical conditions.

Results: Competing senior horses were mainly kept at their owners' own facility, with owners making all management decisions (52.2%). In terms of housing, competing senior horses were most frequently kept in a stall but with ≥12 h a day on pasture. Competing seniors were predominantly 15-20 years of age (73.4%), were geldings (69.5%) and were Quarter Horses (33.5%). About one-half competed/trained for competition at a medium level. Three percent competed at the highest (e.g., international) level. The most common discipline was dressage (32.0%). Stiffness/reduced leg-joint flexibility was the most common owner-reported clinical sign (29.2%; 95% CI: 23.5-35.6) and osteoarthritis was the most common owner-reported veterinary-diagnosed medical condition (32.6%; 95% CI: 26.8-39.0), followed by gastric ulcers (8.0%; 95% CI: 5.1-12.3) and lameness (7.6%; 95% CI: 4.8-11.8). Nearly one-half (43.3%) indicated that their competing senior horse had no veterinary-diagnosed medical condition at the time of the survey.

Main Limitations: Potential recall, response and sampling bias.

Conclusions: Although few horses over 20 years of age were used in competition, senior horses (≥15 years of age) competed up to the highest level (e.g., internationally) in some disciplines. Competing senior horses were affected by medical conditions commonly reported in the general senior horse population (e.g., osteoarthritis and lameness) and younger competing horses (e.g., gastric ulcers and lameness), potentially increasing the complexity of their management.