Animal well-being is a priority for Merck Animal Health. 

The facts are clear.  The benefits and safety of ZILMAX®(zilpaterol) are well documented. ZILMAX has a 30+ year history of research and development and rigorous testing. Worldwide regulatory agencies have reviewed extensive data on ZILMAX and have concluded that use of ZILMAX according to the label is safe in cattle. It is important to understand these data included rigorous animal health safety and well-being studies - conducted by university experts - that found the behavior and movement of cattle fed ZILMAX is normal.    

We are confident that, based on all of the available data on ZILMAX, the experience reported by Tyson is not attributable to ZILMAX. Indeed, Tyson itself points to the fact that there are other possible causes and that it does not know the specific cause of the issues it recently experienced. We will continue to work with Tyson to help it identify those other causes. Again, we are confident that the totality of our data does not support ZILMAX as being the cause of these experiences, and we remain confident in the safety of the product.

ZILMAX has a withdrawal period 3 days prior to harvest. Not for use in animals intended for breeding. Do not allow horses or other equines access to feed containing zilpaterol. Do not use in veal calves. For complete safety information, refer to product label and ZILMAX website.