Infographic: Trace-out Herd Tuberculosis Testing Process

PDF (1,059 kb)

Click on image for larger view
Infographic: Tuberculosis Trace-out Testing. Description follows.

Description of infographic - Tuberculosis Trace-out Testing Process

A trace-out is a herd that has received animals from an infected herd in the past five years.

When a positive case of bovine TB is found all adult cattle that could have come into contact with an infected animal must be quarantined and tested.

An inspector performs two diagnostic screening tests.

  1. Tuberculin is injected into the animal's skin.
  2. A blood sample is drawn.

After 72 hours, the cattle must be re-assembled in order to read the skin test. Any animal that reacted to the skin test or blood test or originating from the index premises will be humanely destroyed.

  1. Any lesions found with suspicious bacteria are tested for bovine TB DNA.
    • Samples are cultured for about 12 weeks in a CFIA laboratory. Any bacterial growth is tested for bovine TB DNA.
    • If the adult cattle test negative, the herd can be released from quarantineFootnote 1.
    • If tissue samples from any adult cattle test positive, the entire herd will be humanely depopulated.
    • A new investigation is done to determine potential spread to other animals and herds.
  2. All samples with or without lesions are sent for culture testing.
    • If the adult cattle test negative, the herd can be released from quarantine. Tissue samples are also culture tested. If there is a positive, a new quarantine will be established.
    • If tissue samples from any adult cattle test positive, the entire herd will be humanely depopulated.
    • A new investigation is done to determine potential spread to other animals and herds.

Total testing time: 14 weeks

Date modified: