04/13/2026
AQHA Update: New Dexamethasone Rule Takes Effect July 1, 2026
The American Quarter Horse Association has issued an important update regarding dexamethasone thresholds that all exhibitors, trainers, and owners need to be aware of heading into the 2026 show season.
Beginning in 2025, AQHA significantly lowered the maximum permitted plasma concentration of dexamethasone from 3.0 ng/mL to 0.5 ng/mL. This change, approved by the AQHA Executive Committee and recommended by the AQHA Animal Welfare Commission in August 2024, reflects a continued push toward elevated welfare standards and medication accountability.
Starting July 1, 2026, enforcement tightens further. Any test results exceeding the 0.5 ng/mL threshold will now be handled under standard positive drug-testing protocols, meaning cases will be formally reviewed and processed under AQHA’s established disciplinary procedures.
Dexamethasone remains a commonly used corticosteroid in performance horses, often administered for inflammation, allergic reactions like hives or insect bites, and respiratory conditions such as heaves. However, with the updated threshold, timing, dosing, and veterinary guidance are more critical than ever to remain compliant.
AQHA strongly encourages members to review Rule VIO405.12 in the 2026 Official Handbook for full guidance on withdrawal times and recommended use.
For more information visit: www.AQHA.com
