Whilst cobalt is an essential trace element and is naturally present in the horse, it may also have the potential to enhance performance when present at concentrations that exceed normal physiological parameters.

International thresholds for cobalt in plasma and urine are published in Section 16 of Article 6A of the International Agreement on Breeding, Racing and Wagering as 0.1 microgram total cobalt per millilitre in urine and 0.025 microgram total cobalt (free and protein bound) per millilitre in plasma.

These thresholds are now introduced into the Irish Rules of Racing with immediate effect.

The following advice should assist compliance with these Rule introductions:

1. A normal racing diet is more than sufficient to meet a horse’s nutritional requirements for cobalt and vitamin B12; neither cases of cobalt deficiency nor disease for which cobalt is the indicated treatment have been documented in the horse.

2. Cobalt is a Prohibited Substance and therefore should not be administered on the day of the race. Further, from evidence to date, and only as a guide, no more than 1 mg of cobalt from a single dose should be given by injection and no more than 5 mg by mouth within the day preceding race day in order to avoid breach of the thresholds.

3. Registered injectable cobalt supplements such as Hemo-15 and Hemoplex offer no nutritional advantages because incorporation of cobalt into the vitamin B12 molecule occurs within the horse’s gut.

4. The safest strategy is the selection of supplements with low amounts of cobalt, or not to use them at all. Vitamin B12 contains cobalt; the simultaneous use of multiple supplements containing cobalt and vitamin B12 risks breaching the thresholds.

Lynn Hillyer, Chief Veterinary Officer/Head of Anti-Doping, 6th April 2017