PCV2 virus hampers pigs’ danger reaction

The pig virus PCV2 has been found to impair danger recognition, according to leading expert Dr Kenneth McCullough from the Institute of Virology and Immunoprophylaxis, Switzerland.

Speaking at an event organised by Merial Animal Health, Dr McCullough explained to vets how PCV2 affects the porcine immune system and its interaction with the dendritic cells – the ones which trigger danger recognition and provide pigs with immunity to disease.

He said that while the double-stranded DNA in PCV2 reduced these levels of danger recognition in the cells, the single-stranded DNA in the virus helped to induce this recognition.

Also speaking at the event, Thais Vila from Merial Animal Health said: “In recent years the symptoms of PCV2 have become less obvious, and may even be sub-clinical. Nowadays, the symptoms may occur later in the pig’s life. The clinical signs can be similar to other viral infections and may depend on co-infections. Symptoms include digestive and respiratory disorders.

“In sows PCV2 affects reproduction including return to oestrus, increased abortions and stillbirths, and pre-weaning mortality. Naïve gilts are particularly at risk from the virus.”

In addition to vaccinating against the virus, she recommended paying attention to key aspects of herd management including: colostrum intake, pig flow management, buildings, hygiene, feed, control of co-infections and genetics.