I will always remember one of my earliest American Association of Swine Practitioners’ meetings. (It was so long ago that the American Association of Swine Veterinarians was still called AASP.)  One particular session on swine dysentery created a heated argument between several of the most respected swine veterinarians of the day. Doctors Al Leman, Hank Harris, Robert Glock, Ralph Vinson and others were discussing the best treatment and control methods for swine dysentery, which was an economically challenging disease facing U.S. pork producers. Several methods were being proposed to treat and then eliminate swine dysentery, but many were not very effective. To make matters worse, treatment plans continuously changed as more information became available.

Finally, a seasoned veterinarian sitting in the back of the room, waiting for his peers to outline the right plan to cure the disease, stood up and said, “Fellas, one of these days we’re going to have to come up with a cure for this problem or our clients are going to start wondering if we know what the ____ we’re doing.”

I remember that as if it happened yesterday, and as I evaluate the progress we’ve made treating, controlling and eliminating porcine reproductive and respiratory syndrome in the past 10 years, the veterinarian’s words ring loudly. 

I do not want to insult anyone by saying that we have not made some great discoveries or that we have not been successful in developing better ways to control and eliminate PRRS. There has been much success in terms of giving producers the tools to eliminate PRRS from infected herds and potentially keeping it out of herds in certain locations. But after the devastating fall and winter that many Midwestproducers have experienced, we still have a long way to go to control PRRS in pig-dense regions. Add in the fact that many producers have spent significant dollars to improve isolation facilities, truck washes, transportation and building design, and I wouldn’t be surprised if some producers now share that old veterinarian’s perspective.

If we could just develop the magical vaccine that would totally control this disease, elimination would be easy. Or maybe it’s time to reevaluate our strategy, and with the tools we have available, develop a plan that just may work.

The current philosophy is to create PRRS-negative piglets regardless if the sow farm is PRRS-naïve and producing PRRS-naïve piglets, or the sow farm has had virus exposure and is “stabilized” to produce piglets that are PRRS-negative.  Most swine veterinarians would agree that this philosophy is the best plan, given the research and information available today. 

Here lies the problem. The industry takes these PRRS-negative piglets and places large groups of them into regions where not all pigs are PRRS-negative. The current philosophy (among many veterinarians, including myself) would encourage producers to not vaccinate these high-health pigs with any of the current PRRS vaccines. By design, the industry has set up the perfect protocol for an acute viral disease to move rapidly though a region and infect many high-health pigs — and high-health sow farms — as it spreads. These large finishing sites with acutely sick, PRRS-viremic pigs may be the infection source for many other sites (including sow farms) in the region. Then the process starts all over again, with sow farms producing PRRS-viremic pigs that move into other areas and potentially infect more pigs. Unfortunately, this scenario probably happened in southern Minnesotaand northern Iowathis winter. 

At some time, we must answer the question, “What comes first, the chicken or the egg?” Do we stabilize the sow farms first, as we are currently doing, or do we stabilize the growing-pig population first? 

As an industry we must continue to produce PRRS-negative pigs. We must try to stabilize our sow farms to gain the huge advantages of high-health pigs. But in pig-dense regions, with the tools we have today, I now believe the best strategy may include stabilizing the growing-pig population first. If we do not stabilize that population, we may continue to infect area sow farms and never actually progress to controlling and then eliminating this disease.

While I agree that none of today’s vaccines are perfect, do they need to be perfect to help us achieve our goal of stabilizing growing pigs? As AASV president, I fully support the eventual goal of eliminating PRRS from the North American pig population. We all agree that we have a long journey ahead, but by working together it may be easier than we think. 

The perfect vaccine may just have to stabilize our growing-pig population, allowing us to use available technology to create and maintain PRRS-negative sow farms. At that point, the job of eliminating PRRS just gets easier.