Efforts by drugmaker Merck to re-introduce its growth-promoting drug Zilmax to the market are “stuck in a kind of veterinary purgatory,” says the NPR blog The Salt. Merck suspended sales in August 2013 amid reports that some cattle treated with Zilmax had difficulty standing or walking. Merck unveiled new procedures for the drug last fall. “But the centerpiece of Merck’s plan, a large ‘field evaluation’ of Zilmax,’ remains in limbo,” says NPR. The study is supposed to look at 240,000 cattle but feedlot operators don’t want to participate because major meatpackers such as Cargill refuse to accept cattle fattened with Zilmax.
Besides the health concerns about the drug, says NPR, meatpackers also have an eye on the export market. Some countries won’t accept beef from cattle that were fed Zilmax.
FERN in 2012 published a story on a related growth-promotor, ractopamine, which was the subject of a trade dispute. Trade partners such as China and the EU banned imports of meat from animals given the drug.