Claims by Southland District Council officials that at least two Southland dairy herds were infected with bovine tuberculosis after infected cows were transferred from the West Coast are unsubstantiated, an Animal Health Board (AHB) spokesman says.
Councillors are demanding a more stringent post-movement testing regime for West Coast cows brought to Southland after a cow from a herd near Edendale was confirmed as having the disease which is hard to contract, and even harder to eradicate.
Another cow, in a herd in the Hokonui area, is still suspected of having the disease after failing a post-movement indicator test in April.
In a statement, council biosecurity manager Richard Bowman said stock in both those herds had tested positive for Tb and that his staff had anecdotal reports of more positive tests involving former West Coast cattle on other farms.
It was "an alarming trend" for a region that had been Tb-free since 2008.
Council chief executive Ciaran Keogh yesterday could not substantiate those anecdotal reports.
However, he was still concerned more than 20 years of concerted effort and expenditure was now jeopardised by the AHB allowing animals to be brought in from an area with a high risk of Tb.
The council was not advocating an end to sourcing West Coast cows.
It wanted im-proved post-movement monitoring so that the AHB visited such herds early, and more often with follow-up visits, to catch dormant disease before cows were shifted to other Tb-free herds around Southland.
"We know that these animals come from an area of significant risk.
They should be managed accordingly."
AHB spokesman Michael Hansen said there was no evidence that more than one Southland herd was infected with Tb, and still no definitive evidence that the one now-culled cow confirmed as infected, and the other suspect cow, had come from the West Coast.
Both animals were identified by post-movement skin tests as suspected carriers, but only blood tests could give definitive results.
Results for the suspect cow were due in the next few weeks, while ongoing DNA tests would confirm where they came from.
Mr Hansen was confident the testing regime was working: the cows were identified soon after arriving in Southland, and they had been dealt with appropriately.
Tb Free Otago board member Mike Lord, whose region has eight infected herds spread across a wide area, said stopping inter-region stock movement was an unrealistically draconian option.
Testing was working: the reality was, the disease had not been eradicated everywhere, so the emphasis had to be on monitoring and control.
