Porcine Reproductive and Respiratory Syndrome (PRRS) Detected in Washington Swine Herd
“Porcine Reproductive and Respiratory Syndrome virus was recently (late May) diagnosed in a small, swine farm in Washington by the USDA National Veterinary Services Laboratory. Please contact your veterinarian concerning implementing vaccination and management measures to reduce the potential incidence of and mitigate the effects of this disease syndrome,” Dr. Brian Joseph, DVM, Washington State Department of Agriculture State Veterinarian.
PRRS was first recognized in the US in the mid-1980’s and was called “mystery swine disease”. A study by the National Pork Board (NPB) in 2011 reported that PRRS Cost the industry $664 million annually. Improved understanding of the disease, pig production, animal health care and management have been able to control the incidences, severity, and impact this disease has had on pig farms. Because Washington state has a small swine industry compared to the Midwest, and the fact that most of our swine herds are isolated from one another, we have not had the incidences/experiences with many of these diseases. This is both good and bad—because of isolation we have been able to keep the disease out, but we also lack experience of dealing with these diseases when they present themselves (which can lead to panic). We have many new and small producers raising pigs and we have many more pigs being transported to Washington state than in previous years—especially this time of year with show pigs moving around to shows and pre-weigh/tag events. So with these new reported diseases in the state, this is good reminders for both experienced and new swine farmers to implement effective herd health programs, that also involve strict biosecurity plans.
“PRRS exist in two distinct forms, reproductive and respiratory, and infected farms may experience one or both. A variety of factors, including swine genetics, the specific PRRS virus variant in the herd, health status of the herd, ages of the animals involved, and pregnancy status, may influence the signs. As a consequence of mutation and recombination, new genetic variants of the PRRS virus appear frequently. Constant genetic change in PRRS virus may explain: 1) the wide variation in clinical disease observed in the field; 2)why prior exposure to one PRRS virus variant may not provide protective immunity against other variants; and 3) why certain vaccines may not be protective in some hers or under certain circumstances.” The Pork Information Gateway, www.porkgateway.org has excellent factsheets about PRRS and PRRS Control/Elimination. In addition, “The Pig Site” has a good outline of PRRS and symptoms at http://www.thepigsite.com/diseaseinfo/97/porcine-reproductive-respiratory-syndrome-prrs/ .
Again, we often talk about the importance of a good biosecurity plan, however for it to be effective, it must be strictly followed. As stated above, in Washington we have been fortunate to not only have low exposure to many of the swine diseases, but isolation (great diseases between swine herds) has helped decreases ability of exposure and spread for diseases like PRRS, PEDv, and Delta Coronavirus. With these diseases (PRRS and Delta Coronavirus) being diagnosed in Washington swine herds recently and with many more pigs being transported within and across state lines, it is critical that we implement effective biosecurity practices and herd health plans to keep Washington swine herds healthy. The Pork Information Gateway also has excellent biosecurity factsheets for farms of all sizes and youth raising pigs, www.porkgateway.org.
By Sarah M. Smith, WSU Extension