The Animal Health Board is responding to a bovine tuberculosis (Tb) infection in a dairy herd in the Awanui area, the third case in that area within three years. Infected cows found in two herds in 2009 had been destroyed, and the herds had since tested clear.
Now positive reactors in a third herd, which was not one of those involved in 2009, had been destroyed.
The board's northern North Island regional co-ordinator, Frank Pavitt, said last week that the exact source of the infection had yet to be determined, but there were number of possibilities.
Checking wild animal populations, especially possums and pigs, was already under way to see if the disease was present in the surrounding area, but while possums were the main source of Tb infection in farmed cattle and deer they had never been identified as a cause in Northland.
Infection could also arise as a result of importing infected cattle, and hunters introducing deer or pigs from other areas to provide sport.
Mr Pavitt declined to specify the number of positive reactors, but the number was irrelevant in terms of the AHB's response and the process to be followed.
It would require two clear whole-herd skin tests six months apart, followed by clear whole-herd blood tests, for the herd to be declared Tb-free.
The AHB, which manages the TBfree New Zealand programme, was also introducing measures to reduce the risk to other cattle and deer herds in the area. Herds within a 10-kilometre radius of the infected property would be tested annually, as opposed to three-yearly as at present, and all neighbouring herds would be tested immediately.
In the meantime very stringent controls had been placed on the farm in terms of animal movements, both to and from the property, Mr Pavitt saying one of the major concerns was that tuberculosis, if unchecked, could find its way into the local wildlife population, which would create an on-going problem for the dairy, beef and deer industries.
TBfree Northland committee chairman Neil MacMillan said while the infection was not good news for the region, with the assistance of the Animal Health Board and local herd owners the issue could be dealt with effectively.
"As the more frequent Tb testing programme is introduced and we step up wild animal surveillance, I urge all land owners to co-operate with contractors in completing their tests and allowing access to their properties," he said.
All cattle and deer herd owners in Northland could reduce their Tb risk by ensuring they registered their herds, met their testing requirements and updated their contact details if they moved properties. That could be done easily via the Tb information line (0800 482-4636) or by visiting www.tbfree.org.nz