In baseball, successful pitchers master the art of throwing a changeup pitch. This is usually a pitch that is thrown to look like a fastball but is considerably slower, about 10 to 15 miles per hour slower. The intent is to fool the batter. The average human cannot detect that the pitch is slower until is about 30 feet from the plate. When the changeup pitch is thrown properly, the batter has already begun the process of swinging the bat. The result is that the batter swings too early, thus missing the late-arriving pitch. Its goal is to disrupt the batter’s timing and concentration, leaving the batter frustrated and confused. It can be one of the most effective pitches in any pitcher’s repertoire.

I apologize right up front for the baseball analogy, but it is fitting as the veterinary profession prepares for the future of how antibiotics are dispensed and used (or not used) on the farm. I believe that the United States Food and Drug Administration (FDA) is about to deliver a changeup to food-animal veterinarians. Through a series of regulatory documents and announcements, the FDA is preparing to eliminate uses of antibiotics for growth promotion and improvement of feed efficiency. The FDA is also preparing to change all feed antibiotics from being dispensed over-the-counter to being prescribed via veterinary feed directive (VFD). While all of this may appear straightforward (ie, a fastball), I believe it to be a changeup that will disrupt the practice of veterinary medicine and the growing of farm animals for food. I am not sure that anyone, including the FDA, has a clear understanding of what this will look like when completed or the impacts on animal health and welfare.

The removal of production uses of antibiotics will present challenges for farmers, veterinarians, and animals. We do not fully understand the health benefit of these antibiotics and may not until they are removed. The loss of production uses of antibiotics will lead to health and welfare challenges for animals, especially those most vulnerable in the early growing phase. The increased use of therapeutic levels of antibiotics is a real possibility. The FDA has not formally stated the goal or measure of success for the removal of antibiotics from the feed, but it is not difficult to surmise that they want an overall reduction in the amount of antibiotics used on the farm. If that indeed is a goal, then the increased use of therapeutic antibiotics may not give the success the FDA is seeking.

The threat of increased morbidity and mortality in growing pigs cannot be dismissed nor ignored. Farmers and veterinarians will need to be prepared to rethink the selection, timing, and duration of antibiotic therapy. The development of new treatment regimens may be necessary in order to prevent, control, and treat bacterial diseases previously held in check by the lower doses of production uses of antibiotics. It would be great to see new label claims for existing antibiotics as well as new antibiotics for feed use.

The FDA has stated that there is the possibility to add disease prevention, control, and treatment uses to the labels of existing antibiotics. Of course this can only be done where FDA deems “appropriate” and “scientifically supported.” This is where the pessimist in me comes out. If we are to believe that the FDA’s goal is to decrease the amount of antibiotics used on farms, then it is counter-intuitive to think that any new label claims will be approved. Another factor weighing against new claims is the economic barrier faced by drug sponsors trying to secure these claims. The cost of research and development, as well as the approval process, is significant and I suspect in most cases, prohibitive. It would certainly be helpful if the FDA could provide a clear and streamlined pathway for drug sponsors to get new label claims approved.

Perhaps the most significant of all the measures proposed by the FDA is the concept of increased veterinary oversight of antibiotic use on farms. This will be accomplished by requiring VFDs for antibiotics used in feeds. How this will be accomplished is an unknown. The FDA has pitched this concept as being straightforward and somewhat seamlessly accomplished. However, the FDA has not yet set in place the explicit details on what will be required on the VFDs or what will be required of the veterinarian writing the VFD. At this point in time, it is difficult to accurately assess the scope and complexity of this endeavor. It is safe to say that putting more antibiotic uses under the oversight of veterinarians will increase the responsibility and the professional liability placed on those veterinarians. Unless careful consideration is given to the practical aspects of the VFD, the time and amount of paperwork involved may prove to be overwhelming.

Increased veterinary oversight does have an upside. The increased involvement of veterinarians in the decision-making process of when and how to use antibiotics is an essential part of the judicious use of these important drugs. Swine veterinarians have committed a great deal of time and effort into the development of effective relationships with their clients and in-depth knowledge of the animals under their care.

Changeup pitches can be hit, but it takes preparation, anticipation, patience, and timing, with a little luck. Likewise, the same factors will need to come into play if veterinarians are to be successful in adjusting to the new regulations governing the use of antibiotics in food animals. Given time to adequately gauge what is coming at them, veterinarians can be well-prepared to assist farmers in making the right decisions.

-- Tom Burkgren, DVM