Do Not Let Our Defenses Down! Report when You See Signs of Blisters and Lameness
Every day is important. Every move is important,” emphasizes Dr. Laura Bruner of Swine Vet Center. One of Dr. Bruner’s farms learned this the hard way. Bruner diagnosed Senecavirus A (SVA) also known as Seneca Valley Virus (SVV) last fall on one of the sow farms she serves. A spur of the moment biosecurity breach likely allowed entry.
“We think it all started with cull truck contamination,” said Bruner. The farm normally uses one designated trailer to take cull animals and one designated trailer for the gilts, weaned pigs, and sow movement. The sow unit trailer broke down. Instead of waiting a day for that trailer to be fixed, they hooked up the cull sow trailer which had hauled culls to a buying station the day before. They went to the GDU, picked up gilts and dropped them off at the sow farm. Subsequently, both the GDU and the sow farm broke with vesicles and lameness.
Bruner and her colleague, Dr. Steve Tousignant, observed extreme lameness in the sows and greater than 60% of the herd with vesicles on the snouts. “Some of the feet were so bad you thought they would never heal, but within a week they started to feel better.” In addition, pre-weaning mortality and stillborn rate doubled for two weeks.
Bruner and Tousignant immediately reported the signs and a Foreign Animal Disease investigation occurred. SVA cannot be distinguished from Foot and Mouth Disease (FMD).
“The consequences of not investigating could be catastrophic if what we suspect to be SVA, turns out to be FMD,” emphasizes Dr. Lee Ann Thomas from the USDA.
With the winter spike in SVA diagnosed cases, Dr. Thomas encourages increased vigilance. Dr. Thomas compliments the US pork industry but adds a concern, “Many individuals are reporting lesions. However, given the spread of SVA, there is a risk that producers and veterinarians could become complacent.” “What is the proper action? Report suspicious cases to your State Veterinarian or Assistant Director, Veterinary Services (VS), so a FAD investigation can be performed by State or VS officials.”
In 2016 and 2017, the Swine Health Information Center (SHIC www.swinehealth.org) along with a contribution from the American Association of Swine Veterinarians (AASV) are sponsoring research on biosecurity and transboundary risk of disease. Dr. Scott Dee at Pipestone Applied Research who has been involved with this research has been testing to see if viruses like FMD could survive an oceanic journey in feed ingredients. Surrogate viruses like SVA have been used to test high risk agents like FMD.
Results show that soybean meal, as well as other ingredients, could be a carrier for many of the surrogate viruses like SVA. In some countries, soybeans might be open air dried. This may be on or near public roads where vehicles travel. In countries where this happens, unwanted livestock pathogens may have contact with these drying feed sources.
If SVA can survive in imported feed ingredients, the inference is that FMD might also survive. “If we get FMD, we are in big trouble,” emphasizes Dee, “which is why this research has impact across all food animal species.”
Dr. Lee Ann Thomas from the USDA expounds, “If FMD were to be detected in the US, it would have a significant economic impact on domestic and international trade of swine, cattle, sheep and goats (all susceptible animals). The more rapid the diagnosis, the quicker the spread of the virus can be mitigated, and economic impacts can be lessened.”
“What did we learn?” Dr. Bruner asks aloud and answers, “You can’t even let your defenses down one time. This farm normally would have a protocol where they had a designated trailer for culls and a designated trailer for their sow movement and weaned pigs. Just that one time that they made an exception . . . it cost them.” “It’s one thing to experience the cost of SVA entering a farm due to a biosecurity breach, it would be another to become complacent with SVA and for us to miss the entry of FMD to the US pork industry,” says Dr. Sundberg. He adds, “I agree with Dr. Bruner. Every day is important. Every move is important. And, when we see signs of blisters and lameness, we must report every time.”
The mission of the Swine Health Information Center is to protect and enhance the health of the United States swine herd through coordinated global disease monitoring, targeted research investments that minimize the impact of future disease threats, and analysis of swine health data. For more information, visit www.swinehealth.org or contact Dr. Sundberg at [email protected]