Zilmax is safe, Merck says. But will the meat industry buy it?

Merck Animal Health SVP of Global R&D KJ Varma

When it comes to cattle feed additive Zilmax, pulled from the market last year on concerning side-effect reports, there's nothing to worry about, Merck ($MRK) says. After a comprehensive review, the drugmaker has determined the product is safe when used according to its label. Now it just has to convince the meat-packing industry.

Concerns that cattle could consume more Zilmax than approved prompted the New Jersey drugmaker's advisory board to undertake the review, it said in a statement Wednesday. The FDA has approved an updated label with a lower dose, and Merck Animal Health has filed to update Zilmax' label in Canada as well.

"The work supporting Zilmax has been complex and time intensive, and we appreciate the time and efforts of the Merck Animal Health Advisory Board, the input and continued support of our customers, and the FDA for its commitment to science and advancing animal well-being," KJ Varma, Merck Animal Health's SVP of global R&D, said in a statement.

But getting meat-processing giants back on board the Zilmax train may be an uphill battle. The livestock drug has been off the market since last August after reports of hoof loss and pneumonia. And in March, Reuters reported new research findings that indicated the number of U.S. cattle deaths linked to Zilmax could extend into the thousands--far higher than the figures Merck reported to the FDA.

Courtesy of Merck

While Merck says those findings are based on unreliable observational data, meat industry behemoths like Tyson and Cargill have stuck by their refusal to take Zilmax-fed cattle. And that's thwarted Merck's attempts to do prove the drug's safety through a planned 240,000-plus cattle study.

And it's not just meat companies that are concerned, either. "We don't want to fiddle with it as long as there's a known animal-welfare issue," Costco VP Craig Wilson told The Wall Street Journal in July. "Costco is not going to agree to take the meat until we've got the right assurances in place."

Meanwhile, Merck's animal health unit has been getting by without the $160 million seller. Animal health sales grew to $885 million for the third quarter, an 11% increase over the year-ago period, the company reported late last month.

- read Merck's release
- get more from Reuters

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