Controlling the misuse of cobalt in horses

Abstract

Cobalt is a well-established inducer of hypoxia-like responses, which can cause gene modulation at the hypoxia inducible factor pathway to induce erythropoietin transcription. Cobalt salts are orally active, inexpensive, and easily accessible. It is an attractive blood doping agent for enhancing aerobic performance. Indeed, recent intelligence and investigations have confirmed cobalt was being abused in equine sports. In this paper, population surveys of total cobalt in raceday samples were conducted using inductively coupled plasma mass spectrometry (ICP-MS). Urinary threshold of 75 ng/mL and plasma threshold of 2 ng/mL could be proposed for the control of cobalt misuse in raceday or in-competition samples. Results from administration trials with cobalt-containing supplements showed that common supplements could elevate urinary and plasma cobalt levels above the proposed thresholds within 24 h of administration. It would therefore be necessary to ban the use of cobalt-containing supplements on raceday as well as on the day before racing in order to implement and enforce the proposed thresholds. Since the abuse with huge quantities of cobalt salts can be done during training while the use of legitimate cobalt-containing supplements are also allowed, different urinary and plasma cobalt thresholds would be required to control cobalt abuse in non-raceday or out-of-competition samples. This could be achieved by setting the thresholds above the maximum urinary and plasma cobalt concentrations observed or anticipated from the normal use of legitimate cobalt-containing supplements. Urinary threshold of 2000 ng/mL and plasma threshold of 10 ng/mL were thus proposed for the control of cobalt abuse in non-raceday or out-of-competition samples.

Challenges in detecting substances for equine anti‐doping

“…Knych et al [41] , Ho et al [42] Ho et al [42] Nickel Schaumloffel et al [44] --Xenon, krypton -Thevis et al [48] -…”

“…[41] The study suggested that regulators should be able to detect administration of a single dose of cobalt to horses. Ho et al [42] conducted an extended study in which the proposed threshold concentrations of 2 ug/L in plasma and 75 ug/L in urine could be used as control limits for the detection of cobalt in horses on race-days. As recommended, a dose of minimum daily cobalt intake for horses through dietary supplements has been reported.…”

Cobalt chloride doping in racehorses: Concerns over a potentially lethal practice

“…It is important that we continue with the development of technologies and assays to detect and control the misuse of cobalt in horses (Ho et al, 2015) and remain prepared to review and refine the urinary and plasma threshold concentrations based on emerging new evidence. If this disturbing trend continues and more unexplained deaths occur, we must focus new research on the effects of physiologically relevant concentrations of cobalt chloride on global patterns of gene expression, protein function and cytotoxicity in primary equine cells and tissues in vitro, make predictions about its bioavailability and pathophysiological effects in vivo and develop sensitive biomarkers to examine its effects on the myocardium.…”

“…Cobalt chloride is a well-established hypoxia mimetic and inducer of hypoxia-like responses, which can cause gene modulation at the hypoxia inducible factor pathway to stimulate EPO transcription and increase its levels in blood (Ho et al, 2015). Cobalt (symbol Co, atomic number 27) is a transition metal in the periodic table.…”

“…Therefore, ill-informed and unscrupulous trainers can easily obtain cobalt chloride and administer it to horses. However, regulatory bodies have recently implemented a urinary threshold of 2000 ng/mL and a plasma threshold of 10 ng/mL for the control of cobalt abuse in non-race day or out-of-competition samples (200 μg/L plasma in Australia and 100 μg/L in Hong Kong) (Ho et al, 2015). ☆ Please note that the content in this Personal View article has not been subject to peer-review.…”