Department of Livestock Veterinarian No. 2 Szymanski said any restrictions on movement should be limited to the herds under investigation, not the state herd as a whole. For the ranches under investigation, the burden is heavy.
“It’s a tough situation to hand over to anyone, in terms of having to run animals down the chute to get tested for TB. With tuberculosis, the test requires two passes through the chute. So there is quite a bit of manipulation depending on where they are in their natural type of management program, they may have already worked animals for the year. Szymanski said.
For a breeder, the test consists of collecting each animal, some of the order of 300 pounds, others well over a thousand pounds, by having them each run through a chute which presses them into immobility so that a test skin may be scratched in its tail. Three days later, each animal should be seen again to see the test results.
Positive animals must be slaughtered and slaughtered, while exposed animals can be placed in quarantine until tested. US Animal Plant Health and Inspection Service records show that twice since last fall, herds in Michigan and South Dakota have had to be “depopulated” – that is, destroyed.
The US Animal Plant Health and Inspection Service reports that bovine tuberculosis was once the biggest killer of livestock in the country and that it took decades of eradication efforts to bring it under control. At the turn of the 20th century, bovine tuberculosis killed more farm animals than all other infectious diseases combined.