Recent positives for aminorex, a drug that has had no commercial source since the 1980s and has no place in racehorses under industry guidelines, has regulators seeking answers and horsemen on the defensive.

There have been positives for the Class 1 drug, which is similar to methamphetamine, in Ohio, Pennsylvania, and Massachusetts in the United States, Ontario in Canada, and Hong Kong in Asia. Officials thus far can’t find a link.

Scot Waterman, DVM, executive director of the Racing Medication and Testing Consortium, said aminorex was known as “Ice” or “Euphoria” when it was in production. But he also said it’s not hard to manufacture.

“At this point, it’s a very fluid situation,” Waterman said during a March 11 presentation to the joint meeting of the Thoroughbred Racing Associations and Harness Tracks of America in Hallandale Beach, Fla. “There are multiple investigations proceeding on a lot of fronts. There are very odd things about this. Certainly, the distribution of the positives is very