Porcine Reproductive and Respiratory Syndrome (PRRS) remains one of the most complex and costly health challenges facing the swine industry, and according to Dr. John Harding of the Western College of Veterinary Medicine, there is no single solution that fits every operation.
Speaking recently about PRRS management, Harding emphasized that producers must weigh multiple factors—biological, economic, and regional—before deciding whether to control, live with, or attempt to eliminate the disease from their herds.
A Costly but Persistent Disease
PRRS affects pigs of all ages and spreads through multiple pathways, including pig-to-pig contact, shared equipment such as feeders and waterers, transportation systems, and even airborne transmission. The disease is associated with increased treatments, higher antibiotic use, elevated mortality, and reduced productivity.
“PRRS is a disease that needs to be taken very seriously,” Harding noted. “It causes a lot of disruption to efficiency and performance, and it’s not going away.”
To Eliminate or to Live With It
For PRRS-negative farms, Harding stresses the importance of maintaining that status through strict biosecurity.
“If you’re PRRS-negative, congratulations,” he said. “Your focus should be on keeping it that way.”
For farms that are PRRS-positive but stable, the decision becomes more nuanced. In some cases—particularly in Western Canada—circulating strains may be less severe, meaning the cost of elimination may outweigh the benefits.
“In those situations, producers may choose to live with the disease,” Harding explained. “It will still cost money, but it may not be excessive.”
Biosecurity Is the Deciding Factor
One of the biggest challenges with PRRS elimination, Harding said, is reinfection risk. He pointed to experiences in the United States, where farms often eliminate one strain only to become reinfected within a couple of years.
“That cycle is largely driven by biosecurity gaps and high hog density,” he said. “Before making a plan to eliminate PRRS, producers need to ask: what is the risk of breaking again?”
In regions with dense pig populations, maintaining a PRRS-negative status becomes increasingly difficult, regardless of on-farm efforts.
Limited Control Options
For operations where elimination is not realistic, control strategies are limited. Vaccination can help reduce the impact of PRRS, but Harding cautioned that no vaccine provides complete protection.
“Vaccination works to some degree, but it’s not 100 percent effective,” he said. “Producers need to have an honest, informed discussion with their veterinarian about what makes the most sense for their operation.”
A Regional Reality
Harding also noted that PRRS often moves across regions in waves, driven by geography and hog density. Farms located near multiple neighboring operations face higher exposure risks, making long-term disease freedom difficult to sustain.
The takeaway, Harding said, is that PRRS management is as much about risk assessment and biosecurity discipline as it is about medical intervention.
