HRNSW Notice - Veterinary Advice - Detection & Withdrawal Times

14 September 2018

Trainers are reminded of their obligation to present horses to race free of prohibited substances and the absolute liability for trainers who are found to have breached Australian Harness Racing Rule (AHRR) 190(1).


Following the administration of a therapeutic substance, a detection time is the first point in time at which a Laboratory cannot detect the substance or its metabolites in the urine or plasma of an animal.

Because of variability in both the animal and the therapeutic substance, detection times may vary. For example, in the case of joint injections, the withdrawal period will depend on both the corticosteroid used as well as the joint(s) injected.

It is therefore necessary for a veterinarian to add a safety margin to a detection time in order to arrive at a withdrawal time. This is the time at which a veterinarian recommends that it can be reasonably assumed that the horse will be free of the therapeutic substance or its metabolites.

Detection times are contained in various industry publications and provide veterinarians a guide for recommending a withdrawal time. In Australia, the Rural Industries Research and Development Corporation (RIRDC) have published a list of detection times for a number of commonly used therapeutic substances (The Pharmacokinetics of Equine Medications ). The European Horseracing Scientific Liaison Committee (EHSLC) have also published a similar list ( ).

It is important to understand the difference between the terms detection time and withdrawal time. A detection time is NOT the same as a withdrawal time.


Prior to the administration of any therapeutic substance it is important for trainers to obtain advice from their veterinarian regarding the withdrawal time for that therapeutic substance which is specific to the circumstances in which it is being administered.

It is recommended that Trainers ask their Veterinarian to provide a withdrawal time using the “clear day” terminology. The introduction section of the Harness Racing NSW Log Book contains the definition of a “clear day”.

Harness Racing NSW provides an elective testing service for a number of long acting substances that may have unpredictable detection times.

For further information, Trainers can contact the Harness Racing NSW Integrity Department.


Michael Prentice                           Grant Adams


Integrity Manager                           Chairman of Stewards


(02) 9722 6600                               (02) 9722 6628