British Equestrian has this week revealed that 75% of the positive anti doping tests they have carried out in 2024 have been as a result of bute.
Phenylbutazone (“bute”) is a controlled medication, meaning it shouldn’t be in your horse’s system at the time of competition due to its ability to affect performance. Competing your horse while he’s under the influence of bute is not only against the rules, but it’s also a welfare risk
Bute can remain in your horse’s system at detectable levels for around seven days, but the exact time will vary depending on factors such as his size, metabolic rate, fitness level and recent medical history. It’s always best to speak to your vet about the recommended withdrawal time for any prescribed treatment, which is the detection time plus an added safety margin, in order to reduce the risk of a positive doping test.
These results are particularly important as many competitors under the rules of member bodies such as British Dressage, British Showjumping and British Eventing keep their equines on competition yards or livery yards where the yard manager or their staff may be responsible for unintentional medication or cross contamination. Bute is a common medication for a range of ailments in equines of all types.
In terms of anti-doping rules, the ‘Person Responsible’ for the horse is normally the competitor who rides or drives the horse during an event, but the owner and other support personnel – including grooms and veterinarians- may also have a level of responsibility in protecting against incorrect medication, poor recording or cross contamination.
On 1 January each year, the FEI publishes an ‘Equine Prohibited Substances List’ (EPSL). This list applies to all horses and ponies competing in any national or international competition at these levels. The list enables Persons Responsible (PRs) for the horse – the rider, owner, groom, parent, etc – to check that they aren’t treating or feeding horses with substances that are prohibited for use during competition, and substances that are not permitted for use in the horse at any time.
The prohibited substance list is made up of two categories…
- Banned substances are substances that are deemed by the FEI to have no legitimate use in the competition horse and/or have a high potential for abuse. They’re not permitted for use in the competition horse at any time
- Controlled medications are substances that are deemed by the FEI to have therapeutic value or be commonly used in equine medicine. Controlled medications have the potential to affect performance or be a welfare risk to the horse
The most recent copy of the FEI Prohibited Substances List is available below:
FEI Prohibited Substances List for 2025
Steps to help reduce the risk can include colour coded feed equipment (such as bowls, scoops and spoons), and understanding the importance of correct recording of medications or veterinary treatment, including and knowing the difference between detection and withdrawal times.
Find out more about equine anti-doping on the dedicated website https://bit.ly/CleanSport_Equine