Testing for bovine Johne's disease

Two types of diagnostic tests are available to test for bovine Johne’s disease (BJD) in live cattle:

1. Blood test (serology) - to detect antibodies in the blood (less accurate, but quick and less expensive). The blood test or serological test for blood antibody is called the absorbed ELISA test.
2. Faecal culture - to detect bacteria being shed in the dung (more accurate, but time consuming and costly). Faecal culture for BJD can be undertaken in two ways: conventional culture; or Bactec culture.

Both actually culture or grow the bacteria.

The contents of this Primefact include the following:

• The advantages and disadvantages of each test
• Why is it difficult to detect infected animals?
• Why can't diagnostic tests give me an absolute assurance that animals are not infected?
• Can the tests be made more sensitive?
• When the tests are used
• Reducing BJD risk using diagnostic tests.