Rita called early in the morning, quite concerned. The piglets in her farrowing house had the scours, and not just scours that starts with one pen and moves to the next until the entire barn is affected. This was scours that broke suddenly, and it was so bad that even the sows had it. You know it’s bad when everybody has diarrhea.
On arrival to the farm, it was learned that the grown pigs had all suffered diarrhea a few days previous. Samples were taken and submitted to the diagnostic lab. What did we test for? What did we find? The suspense was intense.
Suspicions were confirmed that a porcine coronavirus — one that affects pigs — was causing the symptoms. The previous year, several farms in other parts of the country experienced similar symptoms, but laboratory tests were not positive for the diseases we had here. Diagnosticians, veterinarians and researchers worked together to determine that we had Porcine Epidemic Diarrhea (PED) coronavirus here.
The virus was first identified in the 1970s in the United Kingdom and then spread through Europe and Asia. It was first discovered in the U.S. in 2013, with genetic similarities to the virus that was circulating in China. To this author’s knowledge, no definitive link has been determined as to how the virus got here, though there are theories regarding feed ingredient and concerns with travel. Currently, laboratory-diagnosed cases of PED are at or below predicted baseline levels, giving a little hope that we may have the disease somewhat under control.
PED only causes diarrhea in swine. Baby pigs are most severely affected, with near 100% death rates early in the initial outbreak. Affected pigs have watery diarrhea and lethargy. They may not have a strong appetite. Clinical signs typically appear one to four days after exposure and generally last two to three days in an individual pig. It may take a week or more to move through an entire farm, with immunity expected to last two to three months.
There is a vaccine available, and it does provide good protection. The virus does mutate and immunity fades, so there is not complete protection with the vaccine. From the start of the outbreak, biosecurity is key to preventing infection. Cleaning and disinfecting vehicles, particularly those carrying pigs, before they come on the farm is important. Additionally, changing into farm-specific clothes and avoiding coming to the farm if you have been around other pigs helps lower the risk of disease for your pigs. Keeping pigs segregated by age protects those most at risk.
Rita was able to increase biosecurity immediately, because of the forethought that she had put into planning. She was also able to employ others in the family to provide extra nursing care to help many of those pigs that may have died to survive. All in all, she fared fairly well.
It may not be right to draw similarities to our current state of affairs, yet so many lessons can be learned there. Vaccines are here, viruses are changing, and we should still practice good hygiene. It is manageable.