Research: Reasons some farms are more likely to develop a devastating pig disease

PMWS is relatively new to the UK. It was first seen in 1999 and has since become widespread. The disease strikes young pigs from about six weeks after they are removed from their mothers; they then lose weight, have difficulty breathing and can suffer from fever and diarrhoea as they slowly become emaciated. Up to 30% of infected pigs die of the disease.

In this study Pablo Alacorn and Dr Barbara Wieland from the Royal Veterinary College looked at 147 pig farms across England. Their team, led by Professor Dirk Werling, found that the farms with the lowest incidence of PMWS had clean, enriched environments with the maximum amount of space for pigs as possible.

They also found that pigs reared outside were at considerably less risk from PMWS. PMWS is associated with the presence of a virus called porcine circovirus type 2 ( PCV2 ) but the virus alone does not seem to cause the syndrome. Many pigs with the virus do not develop the disease. This suggests that PMWS is only likely to develop when pigs are unhealthy for other reasons.

Professor Werling explains “We found that good animal husbandry is the best way to guard against an outbreak of PMWS. If pigs are reared outdoors, or in an enriched, clean environment, they are far less likely to get sick, even if the virus is present.”

“Our research suggests that by reducing the likelihood of PMWS, improving conditions for pigs is a good investment because, in the long term, production is improved.”

Professor Werling received £2.4M for the PMWS project through the BBSRC Combating Endemic Diseases For Farm-Animal Sustainability programme ( CEDFAS ). As part of the project his team have been working with the British Pig Executive ( BPEX ) to develop monitoring tools to help farmers judge whether their farms are at high risk of PMWS.

Professor Douglas Kell, Chief Executive of the Biotechnology and Biological Sciences Research Council said “Combating animal diseases, both in the UK and internationally, will be crucial if we are to ensure that we can provide safe, sustainable, nutritious and affordable food to all. PMWS is endemic to the UK, but this research demonstrates that the disease can be combated in a way that saves the pig farming industry millions of pounds whilst also improving animal welfare.”

This research is published in the journal Preventative Veterinary Medicine.