Cobalt is naturally found in all animals and animal feed and is considered an essential dietary trace element and micronutrient. Cobalt deficiency is not observed in horses in the wild and the normal diet of horses in combination with the usual prescribed vitamin supplementation should supply the horse with sufficient Cobalt for its well-being and health. Cobalt is classed as a ’heavy metal’ and is a structural component of vitamin B12 (cobalamin). This vitamin is involved in the normal functioning of the brain and nervous system and in the final stages of red blood cell formation and maturation. All of Cobalt’s potential physiological effects in the horse have not yet been determined; however, high doses can present severe toxic effects and can be detrimental to the health of the horse.

Evidence suggests that Cobalt preparations are being used inappropriately in racehorses in some racing jurisdictions. As Cobalt is naturally present in equine biological samples such as blood and urine, it was decided that the introduction of an international threshold for Cobalt is necessary to facilitate the control of misuse in racehorses.

Trainers are advised that the International Federation of Horseracing Authorities (IFHA) has set an international threshold of 0.1 microgram per millilitre Cobalt in horse urine. The NHA, as a signatory country of the IFHA, has adopted this threshold in its rules. This decision was made following a survey which showed that natural levels of Cobalt in racehorses within South Africa correspond to those observed in other countries and that the threshold can be applied to the local population.  Any finding of Cobalt above this international threshold is a Class 3 offence, as detailed in this document.

A large range of registered oral and injectable veterinary supplements which contain vitamin B12 (Cobalamin) or Cobalt salts are available for use in the horse. The administration of any of these could give rise to an elevation of total Cobalt levels in blood and urine. There is not a listing of commercial preparations which contain Cobalt as it will be difficult to keep the list complete. Be aware of the amount of Cobalt provided to the horse (also from dietary sources) and follow the guidance on the NHA website for the withdrawal of products which contain significant amounts of Cobalt.

Note that many feeds contain relatively high levels of Cobalt. Feeds with 0.4 mg Cobalt/kg feed or higher are considered fortified feeds. The use of such fortified feeds increase Cobalt concentration but have not been shown to result in Cobalt levels which would exceed the urine threshold. Note that the use of such feeds would eliminate the need for any other Cobalt supplementation in the horse.

It is recommended that supplemental cobalt from any source, including registered cobalt containing supplements and vitamin B12 (cobalamin), not be administered to the horse within at least two full days prior to race day. Higher doses than those indicated by the product and also repeated administrations may require longer elimination periods. Note that reliance on and use of this guidance does not absolve or diminish a trainer or owner from being responsible for ensuring that the horse complies with the rules relating to the presence of drugs and prohibited substances when presenting a horse.

International Federation of Horseracing Authorities Advisory Document:

Cobalt, additional information

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. In order to provide international consistency regarding the use of cobalt containing supplements, National Racing Authorities may wish to advise the following:

  1. The threshold levels were determined following an international survey of cobalt concentrations in racehorses on race days.
  2. 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.
  3. From evidence to date, 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. Local Rules regarding administration of Prohibited Substances in the period leading up to and including race day must be noted.
  4. Injectable cobalt supplements offer no nutritional advantages because incorporation of cobalt into the vitamin B12 molecule occurs within the horse’s gut.
  5. Trainers should consult with their veterinarians to ensure that their oral supplementation regimen provides only the amount of cobalt necessary to meet the scientifically established nutritional requirements of the horse for cobalt. The safest strategy is the selection of supplements with low amounts of cobalt, or not to use them at all.
  6. Nutritional supplements should only be administered at the manufacturer’s recommended dose and frequency of dosing. The labels of such products should be read carefully every time that they are used.
  7. Many products have not been evaluated to determine if they affect cobalt concentration in the horse. The use of unregistered, inadequately labelled supplements containing cobalt risk breaching the thresholds and is extremely unwise.
  8. Vitamin B12 contains cobalt; the simultaneous use of multiple supplements containing cobalt and vitamin B12 risks breaching the thresholds.