Pergolide has been the mainstay treatment of pituitary pars intermedia dysfunction (PPID) for several decades. | Photo: Erica Larson/The Horse

Pergolide has been the mainstay treatment of pituitary pars intermedia dysfunction (PPID), also known as equine Cushing’s disease, for several decades. Due to the class of drug that pergolide represents, it is a prohibited substance under Fédération Equestre Internationale and United States Equestrian Federation (USEF) rules.

Currently, under USEF GR411, “Conditions For Therapeutic Administrations of Prohibited Substances,” pergolide can be administered, but requires a 24-hour withdrawal from treatment prior to competition, which can represents a hardship to competitor and horse. However, effective Dec. 1, horses that are granted a therapeutic use exemption (TUE) for pergolide can remain on the drug with no withdrawal of drug prior to competition and no need to file a medication report form (MRF) each time they compete.

The USEF recognizes the benefit of this medication in the treatment of PPID-affected horses to normalize the endocrine feedback mechanisms disrupted by this disease. Modeled after TUEs for human athletes that are sanctioned by the World Anti-Doping Agency, the USEF TUE process is intended to sanction the daily administration of pergolide to PPID-affected horses