David Hayes says people should not be "carried away" by the success the international visitors are enjoying this spring.David Hayes drug tests his entire staff on a regular and random basis at his Echuca property. Photo: Getty Images

Senior racing executives are urging trainers across Australia to adopt the policy of leading trainer David Hayes to drug test their staff, following the discovery of the drug “ice” in a Mornington-prepared horse.

Stewards said they were investigating whether Shopaholic, a recent winner at Echuca, was administered methamphetamine — also known as ice — or if the horse was contaminated in taking another illegal substance.