What is the primary TB surveillance test that accredited veterinarians perform for cattle?

The primary tuberculosis (TB) surveillance test that accredited veterinarians perform for cattle is the intradermal caudal fold test. This test is specifically designed to detect latent TB infections in cattle and is essential for the control and eradication of bovine tuberculosis. During the test, a small amount of a purified protein derivative (PPD) is injected into the skin of the caudal fold, which is located on the underside of the tail. After a specified period, usually 72 hours, the injection site is examined for reactions, such as swelling or induration, indicating an immune response to the TB antigens.

The effectiveness of the intradermal caudal fold test stems from its ability to identify animals that may harbor Mycobacterium bovis, the bacteria that causes bovine TB, even if they do not show clinical signs of the disease. This is crucial for preventing the spread of TB within cattle populations and to other animals, including humans. In regions where bovine TB is a concern, maintaining rigorous testing protocols is vital for animal health and food safety.

Other tests mentioned, such as blood tests, are generally not the primary method for TB surveillance in cattle, as they may not yet have the same level of acceptance and