The British Horseracing Authority (BHA) have published a notice regarding their position on altrenogest. This update was published on their website and sent directly to vets and trainers on the 8 March 2019. The update can be seen below:

Following the publication of two notices in 2018 (below), the BHA would like to provide a reminder, and update, on the use of altrenogest in British racing.

BHA Notice – altrenogest (11 September 2018)

BHA Notice – Regumate (21 September 2018)

Analysis of three products which contain altrenogest; Regumate® Equine 2.2mg/ml Oral Solution for Horses (MSD Animal Health), Regumate Porcine 0.4% w/v Oral Solution for Pigs (MSD Animal Health) and the injectable altrenogest (Bova) was performed at LGC (the BHA’s partner analytical laboratory). The results showed the presence of trendione in each of these products. Internationally trenbolone has also been detected in altrenogest containing products.

Trenbolone and trendione are anabolic androgenic steroids, and are Prohibited At All Times under Schedule (G)1 of the BHA Rules of Racing.

The relevant Rules for substances that are Prohibited At All Times can be found in Schedule (G) – Equine Anti-Doping Manual. The associated penalties for these Rules are found in the Guide to Procedures and Penalties 2018.

Due to the above results indicating the presence of trendione in Regumate® Equine, Regumate® Porcine and the Bova product, the BHA would advise that the possession, use or attempted use, and administration or attempted administration of these products could amount to breaches of the Rules of Racing (including that presence of trenbolone/trendione in a sample may result in a 14 month suspension from racing and a 12 month mandatory stand down from racing for the horse in addition to other penalties for the Responsible Person).

As such, we would advise trainers and other industry participants to remove altrenogest containing products (including Regumate® Equine and/or Regumate® Porcine and the Bova product) from all licensed premises, and not to administer any product containing altrenogest to a Thoroughbred from birth until permanent retirement from racing (this includes yearlings/other horses prior to entering training).

Trainers are encouraged to discuss alternative treatments with their veterinary surgeons in the first instance. Further advice may be sought by contacting the BHA Equine Health and Welfare Department on 020 7152 0090 or equine@britishhorseracing.com.

Note: Administration of Altrenogest to Pregnant mares

The BHA have no jurisdiction over Thoroughbred broodmares, provided they have been permanently retired from racing.Treatment of pregnant mares with altrenogest is common. Where any altrenogest-containing product is being administered to pregnant mares as a therapeutic treatment under the prescription of a veterinary surgeon, we would advise that this treatment can continue, in the interests of the welfare of the mare and unborn foal*.

*Altrenogest has been documented to be detectable in the plasma of foals at birth which are born to mares that have been treated with altrenogest from 280 days of
gestation until foaling (1). The BHA are undertaking further work to study the administration of altrenogest to pregnant mares, and determine whether trenbolone and/or
trendione are detectable in foals at birth. Pending the results of this study, we would advise that, where such administration of altrenogest to the pregnant mare is
documented in the clinical notes of the treating veterinary surgeon, no action will be taken by the BHA for that foal following 30 day Notification.
References:
(1) Palm et al (2010) Concentrations of altrenogest in plasma of mares and foals and in allantoic and amniotic fluid at parturition Theriogenology. 74: 229-235