Sealing the barn

Veterinarians work to control air around swine
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Dr. Darwin L. Reicks described swine barns that have airtight seams, air evacuation at entrances, showers and shoe covering areas for workers, and filtration of air that reaches sows.

The measures are largely a response to porcine reproductive and respiratory syndrome, a viral disease that has plagued pork producers since the late 1980s. The veterinarian from St. Peter, Minn., jokingly said that the solution is simple.

"Don't let any unfiltered air into the farm," he said.

PigDr. Reicks was one of several veterinarians at the American Association of Swine Veterinarians annual meeting who gave presentations about the extensive security measures implemented for buildings and shipping containers to prevent PRRS outbreaks. Incoming AASV president Randy G. Jones said the disease causes most of the industry's losses, yet he expressed confidence that veterinarians could reduce its impact.

End may be near

Dr. Scott A. Dee, a professor at the University of Minnesota, said swine veterinarians are ready and able to eliminate PRRS, and a voluntary eradication program could accomplish that goal within a decade.

"Can we think that?" he said. "Can we believe that? Can we imagine that?"

Like Dr. Reicks, Dr. Dee described substantial declines in the number of PRRS outbreaks on farms following filtration. He indicated three farms that previously had yearly outbreaks had lasted more than 900 days without the disease, two other farms had experienced only a single outbreak each during the same period, and five more farms had seen no outbreaks in 500-plus days.

Dr. Dee also indicated that the disease had killed tens of thousands fewer pigs since the filters were installed.

Dr. Montserrat Torremorell, a professor from the University of Minnesota, said that, among PRRS control efforts, attempts to develop a vaccine that would protect across all PRRS strains have received the most attention and funding—but have yielded disappointing results. Existing vaccines are only one tool to be used, along with biosecurity and management strategies, she said.

Dr. Torremorell indicated the relationships among pork producers, livestock veterinarians, academicians, government agencies, and agriculture industries during the fight against PRRS should be a model for research involving other diseases, such as influenza.

Dr. Derald Holtkamp, a professor at Iowa State University, said preliminary figures from a study pending publication will show that PRRS is causing more harm to producers than a previous estimate of $560 million annually. That figure was published in a study in the Aug. 1, 2005, issue of JAVMA.

In the cat-and-mouse game with PRRS, Dr. Holtkamp said, "The mouse is still smarter than we are."

Dr. Holtkamp is director of the AASV Production Animal Disease Risk Assessment Program, which he said provides veterinarians with collected knowledge of risk factors, prevalence, incidence, and clinical outcomes of PRRS interventions. He said the program's database can help veterinarians learn from collected experiences with the virus and use that information to address potential problems.

Dr. Tom Petznick of Norfolk, Neb., has seen surges of interest among producers who want to improve biosecurity on their farms, often in response to disease outbreaks. But inconvenience and cost as well as loss of institutional knowledge through worker turnover cause many of the same producers to become stagnant or lax in addressing risks.

Dr. Petznick encouraged veterinarians to help clients develop multiple layers of protection, preferably simple and inexpensive layers, as well as to ask questions and observe farm employees to make sure they correctly follow procedures.

AASV considers PRRS role

The AASV board of directors turned down a proposal to spend $130,000 to hire a staff member who would direct and coordinate PRRS eradication projects. Board members debated how much information the swine producers and companies involved in those projects would be willing to share as well as whether existing or new staff should be involved in the project.

However, the board approved a motion for AASV staff members to assess staffing and PRRS project needs and asked that the AASV PRRS Task Force further explain the goals for the proposed director.