LICENSED veterinary medicines are well regulated in the UK and undergo rigorous testing and quality control. In some cases, vets need to use medications that have not been specifically licensed in the horse and will usually use medicines that have been licensed and tested in other species (veterinary or human) or for which there are good, published reports to support their use.
Occasionally, vets may need to take a less conventional path and use medicines (often newer treatments) that have had little prior use in the horse.
In all cases, the vet needs to balance the expected benefits of medication against the risks of side effects, while considering the severity of the problem affecting the horse. A case of mild arthritis might receive a dose of a familiar, licensed, equine anti-inflammatory such as phenylbutazone (bute) to
