Infographic: Tuberculosis Testing Timeline

This infographic was developed in the initial phase of the investigation. To learn more on the current status and for the latest information, please refer to:

Fact Sheet: Why do farms have to be quarantined for so long?

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Infographic: Tuberculosis Testing Timeline. Description follows.

Description of infographic – Tuberculosis Testing Timeline

Note: Timeline reflects testing period for single animal.

Day 1 – Cattle are mustered and fed into a chute.

Two screening tests are done:

  • 1) An injection is made near the tail.
  • 2) Blood is drawn and sent to the lab.

Day 4 – Cattle must be reassembled to read the injection site for a reaction.

Blood test results are available from the lab.

Day 11 to 18 – If either test is positive the test-positive animal will be humanely slaughtered.

Non reactors are held in quarantine.

Depending on availability of slaughter facilities, slaughter timeline is variable and takes on average 1-2 weeks.

Tissue samples are shipped to the lab for confirmatory testing.

An enhanced post-mortem is done in all but low risk herds.

Day 21 – Samples arrive at lab.Footnote 1

Histopathology and PCR tests (DNA testing) are done for confirmatory testing.

Day 26 – If results of histopathology and PCR are positive, the infected animal and its entire herd will be humanely depopulated. Samples from reactors and animals with lesions will be cultured for 8-12 weeks for identification.


If results are negative, samples from reactors and animals with lesions will be cultured for 8-12 weeks for confirmatory testing. This herd remains under quarantine.

Day 82 to 110 – The cultured samples are tested through PCR or other methods.

If results are positive its entire herd will be humanely depopulated.


If all adult cattle test negative, the herd can be released from quarantine. Occasionally, a quarantine may have to be extended in order to allow for further testing because of the outcome of herd investigations.

Any culture that tested positive for bovine tuberculosis is sent to Health Canada for strain identification.

Day 170 to 200 – In approximately 2-3 months, Health Canada is able to identify the strain.

Some herds may be subject to re-testing in 6 months.

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