Animal health officials in Oregon and other states are keeping busy as they deal with Seneca Valley Virus, an emerging disease showing up in swine. The virus itself is not necessarily the problem, but since its symptoms mimic the ultra-serious foot and mouth disease (FMD), each report of the virus needs to be checked in order to rule out FMD.
“This virus is important because it’s part of the same family of viruses that causes foot and mouth disease, which is a terrible foreign animal disease that we never want in this country,” says State Veterinarian Dr. Brad LeaMaster of the Oregon Department of Agriculture. “FMD is explosively contagious and can have a huge economic impact on livestock industries.”
Even though Seneca Valley Virus, also known as Senecavirus A (SVA), has been identified in swine herds in the US since the 1980s, it has only been in the past couple of years that the virus has been associated with clinical disease that includes the same vesicular lesions seen in cases of FMD. For reasons not known, the number of SVA cases has dramatically increased this year. Oregon has reported more than 50 cases since early September– all of them connected to the importation of pigs to a slaughter facility in Southern Oregon. A small percentage of pigs that are trucked in arrive with the telltale signs of SVA– blisters on the nose and feet, and general lameness in the animal. Again, the fear that these same symptoms could show up in a case of foot and mouth disease makes it imperative that officials take the reports seriously.
“We are making detections of SVA several times a week and that can cause a huge amount of work for us,” says LeaMaster. “We send a veterinarian to the location to take samples, those samples go to the laboratory, and we wait for the results. The processor can’t market the meat from these animals until we clear those samples from potentially being FMD, which can take a couple of days. It takes a lab test to determine whether the virus is FMD or Seneca Valley. That’s the only way to tell for sure.”
To assist state efforts, the US Department of Agriculture’s Animal Plant Health Inspection Service (APHIS) has dispatched a veterinarian to the slaughter facility to handle the increased work load.
Oregon is not a large state for swine production, which is why the processing facility sources pigs from out-of-state and from out-of-country. SVA expresses itself more often when animals are stressed. In this case, LeaMaster believes the transport of pigs by truck into Oregon is causing the immune system of some animals to weaken a bit, allowing the virus to express itself.
The US has not had a case of FMD since 1929. LeaMaster would like to keep the streak going.
Reports of Seneca Valley Virus in Oregon have been confined to the commercial swine industry, specifically the slaughter facility in the southern part of the state. Nonetheless, anyone raising pigs should be aware of SVA and their responsibility to report any clinical signs of the disease.
“Right now, we are just seeing it in those hogs coming into the state for slaughter, but other states– the big swine producing states– have seen it at some of the animal shows and exhibitions,” says LeaMaster. “For 2018, we want our producers to be aware of the mixing of swine at shows and exhibitions. We have a lot of show pigs in Oregon and those animals sometimes come into contact with swine in or from other states.”
For consumers, the good news is SVA is not transmitted to humans and it is not a threat to the food supply. But for anyone with pigs or associated with the swine industry, the virus is extremely serious only because it shares the same symptoms with FMD. The worst thing producers and others in the industry can do is automatically assume that blisters on the animals are due to Seneca Valley Virus. Failure to identify FMD quickly would likely result in significant and swift spread of the disease, says LeaMaster.
For more information, contact LeaMaster at (503) 986-4680.
