Until the investigation is completed, GAIN has advised customers not feed its equine products to their animals.
Leading horse food producer GAIN Equine Nutrition has commenced an investigation into the presence of a banned substance in its horse feed.
The company said that Zilpaterol, a synthetic beta-agonist approved for use as a performance-enhancer in some beef production systems outside of the EU, had been discovered in some of its equine feed range.
The company said this synthetic substance never formed any part of the formulation of their feeds.
However, its presence was discovered based on positive test results from France Galop, where some of its horses were fed GAIN products.
Further testing of samples in Ireland returned positive results and GAIN has begun contacting all the relevant authorities and customers.
In a statement on Friday, GAIN said: "We are working closely with all appropriate agencies, including the Irish Department of Agriculture, to fully investigate the source of this contamination.
"We will provide a more detailed update once more information is available."
Martin Ryan, Head of GAIN Equine, apologised to customers and said an urgent investigation is underway.
"We apologise sincerely to our valued customers for the inconvenience caused by this incident and we are committed to promptly keeping you fully informed," Ryan said.
"A thorough investigation and trace back of all feed ingredient sources is underway as a matter of urgency to determine how this external contaminant could have found its way into some batches of our equine product.”
