A healthy herd is paramount for the the work we do here on our small hobby farm. We run annual blood tests for the entire herd to be sure everyone is negative for CAE, and we immediately quarantine and test any new animals brought onto our property.
In agreement with what our veterinarians and studies have shown, testing the blood for Johne's and CL is wildly inaccurate, and often times can read false positives resulting in unnecessary cause for alarm. This is especially true on farms who free range poultry around their ruminants.
We instead have chosen to run a fecal PCR for Johne's disease every few years. Fecal PCR's and extended cultures are the only accurate way to test for the presence of Johne's disease, even though blood serology tests are available.
We monitor our herd carefully and do daily health checks on all animals. Any abscesses are treated extremely seriously and result in quarantine and a vet call for fluid to be tested, we have NEVER had a CL+ abscess in our herd.