Impact of transrectal palpation on teaching mares: a retrospective study*

Transrectal palpation (TRP) in mares is considered a noxious and potentially life-threatening procedure, particularly if performed by inexperienced individuals. A retrospective study was conducted using TRP records maintained at the Oklahoma State University College of Veterinary Medicine Ranch. A total of 5,801 TRP were performed from 2019 to 2021 by veterinary students. We hypothesized that in mares the incidence of rectal wall injury and use of intravenous sedation for behavior modification would be low. Additionally, we hypothesized that averse behaviors during TRP would not be a reason commonly cited for mare retirement from the teaching herd. Injury incidence rate was 0.76% (44/5,801) and no injury required surgical correction or resulted in a mare’s death. Sedation was used to minimize averse behaviors 0.34% of the time (20/5,801) and 11 out of 48 mares received sedation. Individual mare use ranged from 1 to 22 years and 10 of 48 mares retired from 2019 to 2021. No retirement was related to averse behaviors or injury experienced during TRP. Findings indicated that student-generated rectal wall injury to teaching mares was at an extremely low rate of occurrence. We also suggest that in live-animal TRP laboratories, animal welfare is not compromised, and it should not be cited as a reason to minimize live animal use within the veterinary curriculum.