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.