PCV3 may be a bigger problem than expected

The emergence of novel porcine circovirus-3 (PCV3) in US pig herds requires closer research into whether the disease is commonly circulating in the country’s hog population, scientists say.

To date, PCV2 has received the most attention from pig producers globally owing to its crippling effects on pigs’ immune systems, reports Pig Progress.

However, recent work by researchers from Kansas State University, Iowa State University and Smithfield have indicated PCV3 needs further investigation to understand its impacts on pig farms.

In a contribution to Journal of Virology, the scientists wrote that the novel circovirus was identified in sows that died with acute clinical signs that looked like porcine dermatitis and nephropathy syndrome (PDNS).

Aborted fetuses from sows with PDNS contained high levels of PCV3, while no other viruses were detected.

Meanwhile samples of skin, kidney, lung and lymph node tissues presented PCV3 in typical PDNS lesions, including necrotizing vasculitis, glomerulonephritis, granulomatous lymphadenitis and broncho-interstitial pneumonia.

These results, the researchers wrote, suggest that PCV3 commonly circulates within US swine and may play a role in reproductive failure and PDNS, and therefore requires more investigation.

Their calls for further research into PCV3 were echoed by a second study carried out by scientists at San Francisco’s Blood Systems Research Institute, the University of California, the University of Minnesota and the Instituto Nacional de Investigación Agropecuaria (INIA) in Uruguay.

The group studied three pigs that had unexplained cardiac and multi-organ inflammation, including a three-week-old piglet from a farm in Missouri, a pig of 9 to 10 weeks of age from a farm in Minnesota and a 19-day-old piglet from a farm in South Dakota. In all three cases, PCV3 was present.

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