Screening Limits- Therapeutic Substances

Like most other international racing jurisdictions, HRA has in place formal screening limits for certain therapeutic substances.  The therapeutic substances assigned screening limits are some commonly used equine medications representing a range of therapeutic classes, including nonsteroidal anti-inflammatory drugs, corticosteroids, local anaesthetics and tranquillisers.

The screening limit is the concentration of a particular therapeutic substance (or its metabolite) in urine or plasma above which the racing laboratory will call the sample positive.

Each screening limit has been derived from previous administration studies involving horses and these limits are harmonised detection limits agreed upon following input by international veterinary consensus.

Two items have recently been amended/added to the International Screening Limits for Therapeutic Substances as referred to in the Australian Harness Racing Rules (AHRR’s).

The two items are:

1. Screening Limits for the purpose of AHRR 188B – Dexamethasone

• 0.02 ng/mL in plasma

1. Screening Limits for the purpose of AHRR 188B – Procaine

• in plasma at 0.02 ng/mL; and,
• in urine at 20 ng/mL

In this instance, the limits are new, as in first time established.  Noting that there has been a Dexomethosone limit in urine for some time, prior to this, the absence of these three levels would result in a positive swab being called by the laboratory.

It has been agreed previously to maintain uniformity to allow for consistent approaches by laboratories and veterinarians across the country.

Contact Stewards in your State with any queries.

Ends.