Why not always use the faecal test instead of the blood test?
Although, as above, it is suggested that the faecal test is a more accurate test, it takes many weeks to grow the bacteria and in most cases, is too expensive to use to test all the animals in a herd. It has also been shown in scientific studies that the use of the blood test and the confirmatory faecal culture test together is the most efficient (time-wise and in accuracy to detect the disease) and economical approach. As positive animals can be missed in the earlier stages of the disease they need repeated testing to confirm that the disease is not present – hence the control program is a long process with regular testing.
