Scott Dee believes the PRRS reign of terror may be over.

Dee spent a 36-year career in the swine industry as a veterinarian in private practice and research. His last 12 years were with Pipestone Research. Though now retired, he remains an asset for the industry as a consultant and continues to pursue solutions to the enigma that is porcine reproductive and respiratory syndrome.

Some studies have put the economic damage caused by PRRS at $600 million a year, with some estimates as high as $1 billion.

Regardless of the dollar amount, PRRS is a disease that needs to be controlled, and Dee believes the industry can do that.

Referring to data from the Dr. Bob Morrison Swine Health Monitoring Project, which has been recording PRRS incidence from about half of the U.S. sow population since 2009, Dee acknowledges the industry has not seen improvement over the years.

“We’re not making much progress, and that’s not good,” he says, admitting that incidence of the PRRS virus coming into Pipestone farms over that time span is at 30% to 50%. “That’s a lot of disease, and that’s kind of where a lot of systems are at.”

Dee says it’s time for producers and veterinarians to take control of this, rather than kowtowing to what PRRS dishes out. How does the industry do that?

“It’s not real rocket science,” Dee says. “We’re just going to take science-based biosecurity protocols in a program that we call ‘next-generation biosecurity.’” Next-generation biosecurity starts with negative breeding stock and a negative semen source, and then focuses on risk factors of viral introduction such as trucks, people, fomites, supplies and feed.

Studies, including those conducted by Dee in the Pipestone system, have shown that viruses can also spread through the air as far as 5 miles; thus, he stresses the importance of filtered sow barns. All Pipestone system barns are negative-pressure, but he acknowledges that positive-pressure barns are also catching on.

Next-generation biosecurity, as Dee calls it, is paying attention to these potential avenues of infection. “The old way is to say, ‘We’ll try this, we’ll try that a little bit.’ It was kind of piecemeal,” he explains. “Here, we’re going to put it all together. We’re going to audit that program, and we’re going to make it standardized, and we’re going to test it to see if it really works.”

A one-year study from July 2021 to June 2022 of 69 Pipestone sow farms across eight states that included 321,000 sows showed only six infections, or 9.7%. “Remember, the Pipestone system used to have 30% to 50% incidence, so by putting this in place, we cut that down to under 10%,” he says.

To rule out a research anomaly, the study was performed over a second year, from July 2022 to June 2023. The Pipestone system had grown to nine states and over 400,000 sows at 76 farms. That second year, results were again below 10% incidence rate.

“This is really good news; just being very good in biosecurity really works,” Dee says. “I think we have the sow farms figured out.”

Focus on grow-finish

“The better the biosecurity in the market hogs, then there is less of a challenge around the sow farms,” Dee notes.

Rachel Stika Jensen is also a veterinarian with the Pipestone system.

“When we look at the textbook definition of biosecurity, the goal is to eliminate or prevent transmission of infectious diseases into our farm,” she says. “So what that means for the swine industry is simply, we need to reduce or eliminate pathogens.”

Just as Dee talks about the importance of collective biosecurity measures on the sow farm, Stika Jensen says the same holds true for grow-finish sites. Secretions of blood, saliva and feces are common routes of viral transmission, and people are great vectors. “We can transmit it very easily on our clothes, our hands, our shoes, as well as our vehicles,” she says.

The U.S. is tops in birth-to-market mortality, with 23% mortality. “This is where we do not want to be No. 1,” she says. “We can improve our biosecurity, and we can definitely improve our mortality. And when it comes to biosecurity, as you all know, we have absolutely everything to lose.”

Stika Jensen encourages producers to look at the five P’s of biosecurity:

1. Pigs. Bring in healthy pigs from viral-negative farms; maintain vaccination plans; and ensure animal entry and exit are done with high biosecurity measures in mind.

2. People. Strict visitor restrictions such as are in place at sow farms should also be instituted at grow-finish sites. Ensure visitors have proper downtime after visiting an infected barn, and at a minimum, Stika Jensen suggests the installation of a Danish bench entry to create a clean-dirty barrier.

3. Property. Producers may not be able to do much about location; they may already be located in a hog-dense area. “This is where layering of biosecurity is so important,” she says. “Maybe we can’t be in the ideal location, but we can do everything else right.”

4. Products. “It’s very tempting to go to Site A and grab a bottle of vaccine, then go to Site B and start treating pigs. Ideally, we need to disinfect that bottle and let it have at least the minimum downtime of one hour,” Stika Jensen says. She also suggests having site-dedicated tools needed for repairs, or that tools and equipment brought on-site be disinfected and have proper downtime before being used.

5. Pests. Birds, insects and rodents are perfect vectors for infections, so it is important to keep bait boxes current and reduce potential habitat.

“Focus on small changes first,” she says, “and we need to focus on education and training. … Our goal in our barns is not perfection, but progress.”

By implementing these systemic changes to biosecurity at sow sites and grow-finish farms, Dee says, “We are now in charge of this virus. Let’s not let it control us. … I think this gives us hope in really tough times.”