Bovine tuberculosis (TB)

Bovine tuberculosis (TB) is a serious, highly infectious disease found in cattle and deer herds, causing weight loss and death.

Possums are the main source and carrier of bovine TB in New Zealand, and the main self-sustaining reservoir of the disease in the wild. In the early 1970s, it was discovered that possums were the source of chronic infection in cattle herds.  Bovine tuberculosis infection transfers relatively easily from possums to cattle and deer due to the proximity of farmland to bush areas in New Zealand. Possums are responsible for around 80% of new infection in cattle and deer herds.

Possum with TB lesion (Source: AHB)

Bovine TB is a major threat to our economy

Dairy and meat exports are worth more than $12 billion annually to New Zealand. Rising international animal health standards and growing concern about food safety are now major factors governing and threatening access to premium overseas markets.

Many of our trading competitors, including Australia, are classed as being free of disease.13 As at August 2009, New Zealand had 0.35%14 of cattle and deer herds infected with bovine tuberculosis. This equates to around 131 herds. As a nation with bovine TB infection, New Zealand is banned from exporting live cattle and deer to TB-free countries, including North America and Australia.

Through a nationally coordinated programme comprising ground and aerial control methods and TB-testing cattle and deer, the Animal Health Board (AHB) (the agency charged with controlling bovine tuberculosis in New Zealand) has, in the past decade reduced the number of TB-infected herds by more than 90%. Aerial 1080 operations account for less than 20% of the AHB's control programme, which also uses traps and a range of pest control toxins.

If AHB's bovine TB eradication programme were to stop, the potential cost to New Zealand as a country has been estimated at $5 billion over 10 years.15 AHB is on track to reach the internationally recognised target for official TB freedom of 0.2% infected cattle and deer herds by 2013.