Greyhounds Australasia (GA) wishes to provide further information to participants in relation to the research which led to the establishment of “testosterone threshold levels in bitches” under National Racing Rule 83(6) effective 1 January 2013, which states:
R83(6) Greyhound to be free of prohibited substances:
Testosterone as evidenced by the presence of5b-androstane-3a,17b-diol at or below a concentration of 10 nanograms per millilitre (ng/mL) in a sample of urine taken from a bitch will not breach the provisions of sub rule (2) of this rule.
The threshold level has been determined following extensive research, analytical studies and statistical analysis, taking into account the variations in natural testosterone levels of bitches and allowing for a statistically-robust margin of safety. The studies also indicate that a bitch in or coming into oestrus is not expected to exceed the threshold.
Specifically, more than 80% of clean bitches studied by Racing Analytical Services Limited showed no 5b-androstane-3a,17b-diol (BaB) at all, and a maximum of 1.03 ng/mL was found in their Australasian study of 187 bitches, with only ten of these animals having a reading over 0.5 ng/mL.
During Testosterone Propionate administration trials, levels of BaB peaked at over 100 ng/ml and remained over the 10 ng/mL limit from under one hour after administration:
- up to 98 hours after 25 milligrams administration to three (3) bitches, and
- up to 120 hours after 50 milligrams administration to another three (3) bitches.
It must be noted that these excretion times are only relevant to the preparation Testosterone Propionate commonly known as Testoprop. Other preparations such as Ropel Liquid Testosterone, Durateston, Spectriol and testosterone implants, may produce significantly longer excretion times.
Furthermore, a study by the Greyhound Board of Great Britain of bitches in oestrus showed very low levels of BaB throughout the cycle. Therefore, it is not expected that a bitch coming into oestrus or inadvertently racing while in oestrus would return a prohibited level of BaB.
Accordingly a new threshold for testosterone was designated, which provides for a certain level of endogenous, or naturally occurring, testosterone to be considered acceptable in a bitch.
GA again reminds participants that it is their responsibility to ensure that a greyhound treated with a testosterone related product strictly complies with the Rules of Racing. Reliance on information in this release will not be a defence in the event of a breach of the rules. It is for general communication purposes only.
