Enzootic bovine leukosis (EBL) is a diesase of cattle caused by the bovine leukaemia virus (BLV). Cattle may be infected at any age including the embryonic stage. Most infections are subclinical but a proportion (30-70%%) over 3 years old develop persistent lymphocytosis, and a smaller proportion (0.1-10%) develop lymphosarcomas (tumours) in various internal organs. Clinical signs if present, depend on the organs affected. Cattle with lymphosarcomas almost invariabley die either suddently or weeks or months after the onset of clinical signs.
There is no treatment for viral infection or for lymphosarcoma in cattle. The most commonly recommended eradication protocol is as follows: 1) identify infected animals using a serologic test, 2) cull seropositive animals immediately, 3) retest the herd in 30–60 days, and 4) repeat testing and cull until the entire herd tests negative. Testing is then repeated every 6 mo. The herd is declared free when there have been no positive tests for 2 yr. Additions to the herd should have two negative tests 30 and 60 days before arrival.
We recommend waiting until calves are at least 6 months old to test. Passive transfer of antibodies can occur through ingestion of colostrum. These antibodies will wane between 4 to 6 months of age.
Submitting samples for Johne's testing is easy. Just mail or drop-off 2 mL of whole blood or 1 mL of serum to us with an ice pack along with your submission form and payment. Please collect blood in red or tiger (grey and red) topped blood collection tubes. Check out our store; if you need to purchase the proper collection supplies.
The BLV test is ran every Friday with results reporting Friday. Please download the submission form if you are interested in fast, accurate BLV testing. The price is just $6.00 per sample.