New Prohibited Drugs for Race Horses

Summary#

The Regulations Amending the Pari-Mutuel Betting Supervision Regulations add several drugs to the list of substances not allowed in race horses and update the listing for zilpaterol. The changes, including an arsenic urine limit of 300 ng/mL, were registered and came into force on June 21, 2022 and were published in the Canada Gazette on July 6, 2022.

What it does#

• Adds Arsenic to section 2 of the Schedule with a urine threshold of 300 ng/mL.
• Adds Hydrocortisone to section 1 of the Schedule (prohibited drugs).
• Adds Mirtazapine to section 1 of the Schedule (prohibited drugs).
• Changes the wording for Zilpaterol (previously listed as “zilpaterol hydrochloride”) so that any preparation, metabolite, derivative, isomer or salt of zilpaterol is clearly covered.
• Keeps the same testing and reporting approach: post-race samples (urine or blood) are tested and positive results are sent to provincial racing authorities for action.

Who's affected#

• Bettors and the general public who rely on fair horse racing.
• Horse owners, trainers and veterinarians involved in racing.
• Racetracks and racing stables that must ensure horses are free of these substances on race day.
• Testing laboratories that analyse post-race samples.
• Canadian Pari-Mutuel Agency (CPMA) and provincial racing commissions, which run and enforce the drug control program and Rules of Racing.

Why it matters#

• These changes aim to protect the integrity of pari‑mutuel betting by reducing the risk of drugs being used to alter a horse’s performance.
• The 300 ng/mL arsenic threshold recognizes that low levels can occur naturally, while still controlling higher, performance‑affecting levels.
• Clarifying the zilpaterol entry closes a potential loophole by covering all forms and related chemicals.
• In practice, owners and trainers need to avoid using these substances before races; testing labs will detect positives and provincial commissions can impose penalties under their racing rules.