United States Eventing Association

As a result of a number of recently reported equine fatalities associated with the use of Medroxyprogesterone (MPA), US Equestrian will reconvene its MPA Panel to further analyze the use of this substance in horses competing at USEF-licensed competitions.

This latest information on equine fatalities associated with the use of MPA underscores the need for the MPA Panel to meet and review the critical information about this substance in order to provide our members with the information they need to protect their equine partners.

The MPA Panel was first convened in the winter to 2017 due to discussion in the veterinary community and the emergence of research regarding the efficacy of MPA in competition horses. Specifically, the question focused on how MPA affects the competition horse, since research indicated that MPA does not interrupt estrus in mares. This was especially important due to its increased use in geldings and stallions, and also to the reports of increased dosages being administered.

Following discussions at public hearings and town halls, as well as feedback from our members, the MPA Panel recommended that we continue to monitor the use of MPA, including implementation of MPA-specific medication reports in order to capture more information on dosage, administration schedules, and the continued presence of the substance in a horse’s system after the last known administration. However, the recent reports of equine fatalities have raised greater concern regarding the safety of this substance in horses.

US Equestrian remains steadfast in our efforts to protect human and equine athletes. As such, we will update our membership on any changes to the permitted use of MPA. In the interim, USEF strongly discourages the use of MPA by its members and also recommends that you consult with your veterinarian.