Preventing PRRS

You cannot see or smell it, yet this silent killer causes reproductive failure in sows and respiratory disease in young pigs.

Every time someone opens a door, this uninvited guest enters the barn. It rides in with the slightest breeze, hitchhikes on clothing, skin, equipment, supplies — anything that comes onto the farm. Once pigs are infected, they pass along the disease, known as porcine reproductive and respiratory syndrome virus.

A PRRS break on a farrow-to-finish hog farm can cost the owner an average of $200 per sow. Nationally, PRRS costs the industry $565 million per year.

Key Points

• PRRS costs hog farmers $200 per sow.

• Trial uses extensive filtration to eliminate the virus.

• Lab and boar farm trials report decreased incidence of PRRS.


The disease has hit Minnesota hog farmers hard. It first appeared in North America in 1987 and shortly thereafter in the state. It baffled veterinarians, who simply called it “mystery swine disease” until they learned its etiology. Early attempts at treatment and control were limited as PRRS continued to re-infect herds.

Frustrated by the lack of knowledge and treatments, veterinarian Scott Dee left private practice and joined the University of Minnesota in the early 1990s to further study PRRS. Over the last six years, Dee and his collaborators have worked to contain PRRS by closing herds and evaluating barn air-filtration systems. Results from filtration were so positive in lab trials and on boar farms that they decided to expand their project to include commercial farms involving large numbers of pigs in a swine-dense region.

Three veterinary clinics joined the trial — Fairmont, Pipestone and Swine Vet Center in St. Peter — along with several client farms. Make Line Ridge, Fairmont, a 2,500-sow farm owned by Kevin Hugoson, began making facility changes and upgrading bio-
security procedures specifically for PRRS over the last year, with guidance from Fairmont veterinarians Paul Ruen and Jeff Kurt. Employees have been retrained and educated about PRRS transmission. Structural tweaks have been made throughout the barns to button them up and filter incoming air. An on-site animal compost barn was built to further reduce disease transmission from incoming trucks.

Thus far, the impact on herd health has been positive. The herd hasn’t had any new introductions of PRRS. Before, the disease had been an annual occurrence. Hugoson is encouraged yet cautious about disease control over the next several months.

“The true test will come this winter,” he says. “Last fall we had a cold October, so we were late in getting everything in [building upgrades and employee training]. We had a ton of details to manage, and employees had to put them in place. We’re on a learning curve.”

Assistant manager James Spencer says employees work hard at animal care, and they strive to do the best they can to raise healthy pigs.

“Everyone is eager not to have PRRS,” he says. “It’s demoralizing when we have had outbreaks and you see aborted pigs. It’s a killer.”

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Leading the charge: (left to right) Make Line Ridge herd owner Kevin Hugoson, veterinarian Paul Ruen and assistant herd manager James Spencer, along with the farm’s employees, are working to eliminate PRRS on the 2,500-sow farm.

This article published in the November, 2010 edition of THE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.