Animals Euthanized With Pentobarbital Should Not Be Rendered

Rendering companies provide an important biosecurity function through the collection and processing of animals that die other than by slaughter, including on-farm mortalities. Rendering is the preferred method for handling animal byproducts and mortalities with the rendered products, such as meat and bone meal and tallow, frequently used as ingredients in nutritionally balanced foods manufactured for livestock, poultry and companion animals to consume.

The cooking process used is validated to kill conventional pathogens, such as bacteria and viruses, but will not inactivate chemical hazards such as pentobarbital. The U.S. Fish and Wildlife Service (FWS) published the FWS Fact Sheet Secondary Pentobarbital Poisoning of Wildlife ( which discussed reports from 16 states where bald and golden eagles, other wildlife and domestic dogs died after scavenging pentobarbital-euthanized animals. FWS concluded that pentobarbital-euthanized carcasses should not be rendered nor, should they be disposed of where wild and other animals can access the carcass.

The Food and Drug Administration (FDA) also has determined that pentobarbital is a hazard in ingredients fed to pets and other animals and that animals euthanized with pentobarbital cannot be rendered to make foods for pets, poultry and livestock. FDA has a zero tolerance for pentobarbital in animal food. Renderers cannot distinguish euthanized animals from animals that die from other causes and the rendering process does not inactivate pentobarbital. For euthanized livestock or other large animals to be rendered, non-chemical forms of euthanasia must be used.

Kerry Courchaine, Director of Technical Services at Darling Ingredients Inc., shared that Darling has found an alarmingly high rate of pentobarbital residue in rendered products here in Iowa.  In fact, the number of pentobarbital residues observed in Iowa is one of (if not the highest) anywhere in the country.  It’s not clear whether the contaminated carcasses are from cattle, small ruminants or other species of animals; but dairy, beef, and small ruminant owners need to be aware that if they have animals euthanized with pentobarbital by a veterinarian, these animals should not be rendered.

Officials from Darling Ingredients Inc. note that they have implemented procedures to keep pentobarbital out of the rendering stream. They no longer accept horse mortalities for rendering; have attempted to educate various stakeholders on the importance of the issue; and require raw material suppliers to sign a barbiturate hazard control warranty before scheduling collection. The detection limit of the method FDA uses to test for pentobarbital is so low (less than 10 ppb) that rendering one euthanized cow or horse of average size could contaminate an entire day’s production of finished fat and proteins with detectable levels of the drug. In a letter to veterinarians, Darling Vice-President C Ross Hamilton noted, “If we are unable to demonstrate that our preventive efforts are effective at controlling pentobarbital, we may be forced to curtail animal mortality collection practices in certain regions or in all areas to comply with the FDA regulations.”

Ross also explained disposal of animals treated or euthanized with pentobarbital is problematic. Such animals can no longer be rendered and other methods such as abandonment, shallow burial and composting can result in secondary poisoning of wildlife and domestic dogs. Livestock owners and veterinarians responsible for such unintentional poisonings may be held liable and subject to fines and/or criminal prosecution under federal laws.

Since it may be necessary to use pentobarbital, veterinarians should guide the animal owner with written guidance indicating the limitations for disposing of the carcass. Additionally, having an established method for permanently marking animals euthanized with pentobarbital would provide a means for renderers to identify animal remains that cannot be rendered from those that can and should be.

For more information producers should contact their renderer or their veterinarian.

Leave a Reply

Your email address will not be published. Required fields are marked *

Join our Mailing List

Enter your email address:

Delivered by FeedBurner