With the U.S. Food and Drug Administration’s (FDA) guidance on antibiotic use in food-animal production, some confustion and many questions have surfaced. The new guidance calls for voluntary suspension of antimicrobial use for growth promotion purposes and more veterinary oversight in the form of Veterinary Feed Directives (VFD). FDA is giving companies three years to work through the process.

To address some of the questions and provide media with clarifications, representatives from the American Veterinary Medical Association (AVMA), National Pork Producers Council (NPPC) and the Animal Health Institute (AHI) spoke with reporters this week.

“Antibiotic used in food-animals are regulated by FDA under the same laws as products for humans are regulated under,” said Ron Phillips, AHI’s vice president of public affairs. He pointed out that companies have to provide the same kind of proof of safety and efficacy before products are approved. FDA allows four efficacy label claims for antimicrobials:

  • Disease treatment
  • Disease control-- such as during a disease outbreak.
  • Disease prevention-- when a veterinarian determines an outbreak is likely.
  • Growth promotion—which increases an animal’s weight gain or feed efficiency

The first three are considers to be therapeutic uses, while growth promotion is a sub-therapeutic use. “Regardless of the antibiotic, producers and veterinarians must follow the label when administering the product,” Phillips said. “They are very tightly bound to what they can and can’t do.”

Christine Hoang, DVM, AVMA’s assistant director of scientific activities, said the association supports the collaborative approach FDA has taken in developing the new guidance. “AVMA is a strong proponent of having antimicrobials available to ensure animal health and wellbeing,” she said. “But at the same time, we are also concerned about public health and food safety.” AVMA has formed a steering committee to work with FDA in specifying veterinary oversight provisions in the guidance.

Representing the pork industry, Liz Wagstrom, DVM, chief veterinarian for NPPC, said that the loss of subtherapeutic antimicrobials, is expected to result in more sick animals and higher cost of production without any real public-health benefits.

“We’ve always been supportive of veterinary oversight and judicious use of antibiotics,” she added. “A veterinarian should always be involved in the decision-making process.” But FDA’s guidance also raises concerns that the requirements could cause hardships for producers running smaller operations and those in remote areas that cannot afford or do not have access to veterinary support to obtain the required VFDs.

AHI’s Rich Carnevale, vice president of regulatory, scientific and international affairs, said the association and its members appreciate FDA’s concerns over the use of medically important antimicrobial products for growth promotion. “Many of our animal health companies (AHI members) are human health companies too,” he pointed out. Thus they have a strong interest in preserving the efficacy of those products.

He reiterated that AHI supports FDA’s position that claims for treatment, control and prevention qualify as therapeutic use and that preserving those applications for veterinarians and producers is critical.

“There’s much work to be done and the devil is always in the details,” Carnevale said.

In fact, FDA has to get the final VFD proposal published, which is “key to all of this,” he added. Companies will have to begin working on changing product labels, conducting new studies and in some cases resubmitting label requests for dose and duration.

While it’s up to individual companies, AHI expects that over the next few years, that some will pursue new therapeutic claims for products that lose their growth-promotion claims. In countries where sub-therapeutic uses have been banned, such as in Denmark, therapeutic use of antibiotics have increased. This suggests sub-therapeutic use helps suppress and prevent disease outbreaks, along with promoting growth.

“We’re very confident that growth promotion levels have had disease prevention impact, which is why we’re concerned about seeing more sick pigs,” Wagstrom added.

Gaining approval for new label claims will, however, require extensive investment in research trials and data collection. The product will undergo a complete testing and approval process through FDA, assuring a specific use is efficacious and safe Growth promotion, Carnevale says, is a relatively easy claim to demonstrate in research trials. Proving the efficacy of low-level feed-additive antimicrobials for suppressing sub-clinical disease is more complex.

In the end, “we see FDA’s new guidance as strengthening the veterinarian/producer relationship,” Wagstrom said. “It may shift some of the decisions toward different management practices on the farm. It will be a transition period for the next three years.”