LABORATORY

CLENBUTEROL

Special notes on positive findings of Clenbuterol

Clenbuterol is a therapeutic substance found in a local veterinary product for oral administration. As a bronchodilator with action to “reduce reversible airway obstruction” it is primarily prescribed for horses which suffer from Chronic Obstructive Pulmonary Disease (COPD). This condition described as “difficulty to breathe, often progressively getting worse” is quite prevalent in South Africa due to sometimes dusty stable environments and dry climatic conditions. It is frequently prescribed to racehorses as part of a treatment regimen extending over several days.‚Ä®Internationally the IFHA has assigned Clenbuterol as an “anabolic agent” with a classification corresponding to the NHA guidance of “Class 1”. This classification applies to the substance type “beta-2 agonists”, to which Clenbuterol belongs. This IFHA “Class 1” classification applies “unless the substance is prescribed by a veterinarian as a bronchodilator”. The reference to its anabolic effects is as a result of studies indicating that it increases muscle mass and protein synthesis as observed in animals.
As a signatory country, the NHA aligned its classification to Class 1 (Forbidden Substance), as shown in this document. The classification is however also conditional to “unless the substance is prescribed by a veterinarian as a bronchodilator”, upon which a classification of Class 4 applies.

When a positive finding of Clenbuterol is declared in the racehorse it is important for Inquiry Boards to consider the circumstances surrounding this positive and which classification is to be applied.

To be considered includes the aspects:
  • The Clenbuterol preparation “Ventipulmin” is a powder which is administered orally and will often be stored in the feed room. The possibility therefore exists that this could end up in the incorrect horse’s feed.
  • Clenbuterol treatment is often a treatment regime of several days (for example 7 days or more).
  • The elimination of multiple doses of Clenbuterol from a horse can be detected for at least 6 days.

Inquiry boards which have to adjudicate on positive findings for Clenbuterol must therefore be mindful that if there is any another horse in the particular stable yard which has been correctly prescribed and recorded Clenbuterol, then there must be consideration to have the offence classified as Class 4, not Class 1 (Forbidden Substance).