At the end of September, rule change proposals were posted for comment on the US Equestrian website. One of those proposals is Tracking 023-26, which relates to the use of dexamethasone in USEF-licensed competition. Dexamethasone is a corticosteroid commonly used to relieve swelling, redness, itching, and allergic reactions in horses, and can be given intramuscularly, intravenously, or orally. Submitted by the USEF Veterinary Committee, this proposed change to GR410 would move dexamethasone from a quantitatively permitted substance to a prohibited substance in competition.
This rule change proposal is a result of the change US Equestrian made earlier this year to reclassify cetirizine (commonly known by the brand name Zyrtec®) to a permitted substance, meaning it can now be used in competition. Cetirizine is a second-generation antihistamine often used in horses to reduce allergic skin reactions or other seasonal allergies. First-generation antihistamines, such as hydroxyzine, readily cross the blood/brain barrier and can have sedative effects in horses. Cetirizine is an active metabolite of hydroxyzine, but it acts peripherally and does not cross the blood/brain barrier readily, nor does it have apparent sedative effects on horses. First-generation antihistamines remain prohibited substances in competition.
With cetirizine available to treat hypersensitivity reactions, the need for dexamethasone has decreased.
“Because cetirizine has been reclassified as a permitted substance, the Veterinary Committee wanted to eliminate the use of dexamethasone for treating or preventing allergic reactions because corticosteroids can have negative effects on horses,” said Dr. Stephen Schumacher, Chief Veterinary Officer at US Equestrian and staff liaison to the Veterinary Committee.
While this proposal would reclassify dexamethasone as prohibited, the medication could still be used in compliance with GR411, which outlines the conditions for using prohibited substances for therapeutic uses and requires the timely submission of a Medication Report Form.
Per GR414, dexamethasone may still be used to treat acute urticaria (hives). For that use, horses competing at USEF-licensed competitions may receive a dose that does not exceed 0.5 mg per 100 lbs if administered more than six hours, and less than 12 hours, prior to entering the competition ring. If a competing horse receives dexamethasone, as per GR414, it must be administered by a licensed veterinarian no less than six hours prior to competing. The trainer also must submit an Equine Drugs and Medication Report Form before the horse competes.
Members are invited to comment on this rule change proposal and any other General Rule proposals here. Comments are open until February 15, 2027, at which time the proponents may choose to submit a second draft. Draft 2 of General Rules and Draft 1 of the Discipline Rules will be open for member comment again on March 1, 2027. To view the proposal, jump to Tracking #023-26, where you will be able to download the rule change proposal as well as leave a comment.