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Medroxyprogesterone Advisory

December 1, 2020

The Canadian Pari-Mutuel Agency (CPMA) is advising veterinarians and race-horse trainers and owners that medroxyprogesterone is a prohibited substance in Canada because its use has been associated with deaths in horses and approved veterinary products containing this substance are not available in Canada. In addition, there is published information supporting its lack of efficacy in suppressing estrus, its main reason for use.

Products containing medroxyprogesterone should not be administered to a race-horse for any reason.

Medroxyprogesterone can be detected in post-race samples for an extended period of time, and may result in a positive test.

Testing for medroxyprogesterone will begin on June 1, 2021.

The CPMA strongly recommends that you consult your veterinarian on any decision to administer supplements or medications to a horse.

If you have any questions, please contact the CPMA at 1-800-268-8835 or