AR.177B(2) is the list of specified substances and categories of substances for the purposes of the out-of-competition testing rule AR.177B in thoroughbred horse racing. These substances are considered to have no place for use in racehorses, and their detection in a sample taken from a racehorse at any time, including out-of-competition, or their discovery in a racing stable are considered serious offences, with penalties of mandatory disqualification for any person found to have administered, attempted to administer or was a party to the administration of these substances.

The list is updated from time to time to accommodate new substances and classes of substances that are identified by Racing Australia as risks to the integrity of racing and to the welfare of horses.

Additions to the list of specified substances in the out-of-competition testing Rule AR.177B(2)

Veterinarians should be aware of the three new categories of substances added to the list in AR.177B(2) from 1 November 2016:

“(g) haematopoietic growth factors, including but not limited to filgrastim.”

This class of substances is banned by the World Anti-Doping Agency (WADA) in human sports due to their effects on blood parameters in the biological passport, and as masking agents for other substances. There is no legitimate place for their use in racehorses.

“(l) corticotrophins, including adrenocorticotropic hormone (ACTH) and tetracosactrin (tetracosactide), and corticotrophin releasing factors.”

This class of substances is also banned by WADA, and they are used to stimulate the adrenal gland to produce the body’s natural cortisone and other steroid hormones. They raise an integrity issue because of their ability to affect performance, their potent effects on a number of body systems and their anti-inflammatory effect.

“(w) zoledronic acid and any other bisphosphonate drug not registered for veterinary use in Australia.”

The bisphosphonates are used to treat osteoporosis in humans and a range of bone conditions in horses. Their use, however, has been associated with an increased risk of spontaneous fractures due to the poorer biomechanical properties of the new bone produced arising from the inhibition of the activity of osteoclasts during bone remodelling.

There is a registered veterinary preparation (Tildren) available for use in horses, and its judicious use might be indicated in selected cases. However zoledronic acid (which is not registered for use in horses) has between 100 and 10,000 times the potency of the registered drug Tildren. 

The major concerns of racing authorities worldwide regarding the use of bisphosphonates in racing horses are their prolonged analgesic effect and that they may predispose racehorses to major fracture when competing, especially when given to horses with certain pre-disposing conditions.

The complete list of substances specified in AR.177B(2) can be found in the Rules of Racing of Racing NSW which can be accessed at:
http://www.racingnsw.com.au/site/_content/document/00000401-source.pdf

Dr Craig Suann
Official Veterinarian
Racing NSW