Greater Wellington manages bovine tuberculosis (Tb) vector control operations in the region, under the Animal Health Board's national pest management strategy, to reduce the incidence and prevent the spread of bovine Tb in farmed cattle and deer herds. This protects the viability of cattle and deer farming in the Wellington region and New Zealand's export trade in beef, dairy and venison products.

Our bovine Tb possum control operations - covering about 400,000 hectares - have been very successful. The control strategy of maintaining possum numbers at low levels has resulted in a substantial reduction in the number of cattle and deer infected with bovine Tb.

The operations have helped dramatically reduce the number of infected cattle and deer herds in the region, down from 331 in 1994 to 22 in the 2003/4 year.

Bovine Tb is an infectious disease, which is one of New Zealand's most serious animal health problems. It can affect the throat, lungs and associated lymph nodes, but can also affect other organs and can develop into a chronic condition causing wasting and death.

Bovine Tb infects cattle and deer and a wide range of wild animals, especially possums, ferrets and pigs. Livestock in New Zealand are most likely to catch Tb from contact with infected wildlife who discharge tuberculosis bacteria. Infected wild animals which spread Tb to livestock are called vectors.

If Tb is not controlled, it could put at risk our multi-billion dollar export markets for beef, deer and dairy products. The cost of trade barriers and restricted export markets for our primary produce would be huge.

Parts of the Wellington region are populated with Tb infected wildlife, such as possums, ferrets, wild deer and wild pigs. These animals can be a source of infection and re-infection of cattle and deer herds. So to successfully reduce Tb in livestock, it is critical to reduce the populations of vectors. The principal focus of vector control operations are possums and ferrets. Feral pigs and deer are not normally targeted unless it can be proven that they are implicated in transmitting the disease to domestic animals.

Greater Wellington's Biosecurity department manages the overall bovine vector control programme and tenders out the actual control work.

The physical operations in the field are carried out by various professional pest control organisations, including BioWorks. BioWorks was previously Greater Wellington's bovine Tb works unit. This unit, which carried out bovine Tb possum control operations in the Wellington region for a number of years, now operates as a stand alone business unit under the new name. You can find more information about BioWorks here.

If you have any questions, or need some advice about bovine Tb operations, please contact Greater Wellington biosecurity staff in Masterton on 06 378 2484.