years ago I had an animal that was suspect on both of the skin tests. I had to chose to either kill the animal to prove he did not have TB or I had to be quarantined for 90 days. I chose to take the indemnification for the animal and had the animal killed. That is one nice thing about TB is that there is indemnification for that disease. The feds paid $3000 and the state of Wisconsin added another $1500 so I received a total of $4500 for that one animal. I know that isn't the best if you have a high dollar animal, but that is a choice each farm must make. From what I am hearing with the blood test, if an animal is a suspect with the first blood test, USDA does a second test with the same sample using a test that is better than the first, but more costly. If the animal is suspect to both tests, you can draw another blood sample in 30 days. I am not up to date on the next step, but I would guess it would be similar to the 90 day quarantine of the skin test before another blood test can be taken???
Every farm needs to decide what is best for them....the cost of the blood test is much higher than the skin test, but not having to handle the animals twice is worth quite a bit in my mind.