Identifying bovine TB

Identifying bovine TB

Cattle and deer

In cattle and deer, the disease is most commonly found as small lesions in the lymph nodes of the chest. In more advanced cases, lesions are filled with a gritty or pus-filled mass and can be found in the lungs and other organs. The disease can lead to chronic wasting and eventual death. Advanced TB like this is now uncommon in farmed animals in New Zealand because TB testing programmes usually detect the disease at an early stage and animals are culled. 

TB lesion in cattle


Possums are unusually susceptible to TB and the disease quickly progresses to an infectious stage. Possums with advanced TB can have visibly swollen lymph nodes at the groin or armpits which can turn into weeping, pus-filled sores. These sores can vary from a cream/green abscess to white, gritty lesions and can be just a few millimetres across to up to 60mm in diameter.

Feral pigs

For pigs, TB can usually be found in the lymph nodes at the base of the jaw bone. It can sometimes also be found in the intestines. 

TB lesion in pig

Copyright [2012] by OSPRI