The South Island was clear of the contagious viral disease, post-weaning multisystemic wasting syndrome (PMWS), until young pigs began to die at about 14 piggeries, from the south of Christchurch to Ashburton.

Samples of the virus have been sent, together with North Island samples, to the Australian Animal Health Laboratory in Geelong, Victoria. The two samples will be compared to confirm that the disease is PMWS.

Massey University animal health expert Professor Roger Morris said the results of the laboratory work would provide the final proof that the syndrome was responsible for the pigs' deaths. "I think we are satisfied that it is PMWS, and the Christchurch sample has given us the opportunity to check this out.

"We have got some promising indications from the work we have already done that there is a virus in there. The samples will be compared with our experimental transmission study (in the North Island)."

In this study, scientists proved the disease could be transmitted direct by pigs in close contact and from short distances away.

Source: Stuff.co.nz