BVD is one of the most significant pathogenic viruses in cattle. It challenges producer profitability and animal health across the dairy and beef industries with increased reproductive losses and higher cost of gain. Cattle infected with BVD can shed virus through virtually any bodily fluid making it one of the highest contagious diseases in cattle herds. Some calves born persistently infected (PI) with BVD virus posing a serious threat to the health of the herd. PI calves are born from a pregnant cow that is exposed to BVD virus during the first 5 months of gestation. These PI calves may be born weak, deformed or may appear completely normal yet always shed large amounts of virus into their environment, causing a wide array of health problems within a herd or pen. Increased respiratory disease (pneumonia), diarrhea (scours), and reproductive failures (abortions, mummifications, congenital defects) are the main symptoms of cattle challenged with BVD virus.
The BVD test detects BVD virus particles in the sample. Either serum or ear notches can be used for testing.
Only serum samples from pre-colostral newborn calves or calves older than three months of age are suitable for testing with the Enzyme-Linked Immunosorbent Assay (ELISA). Maternal anti-BVDV antibodies , which can be passed to newborn calves in the first 24 hours of colostrum intake, can interfere with the ELISA test to produce false-negative results in PI calves.
Animals of all ages, including calves less than three months of age can be tested for persistent BVDV infection using the ear-noth BVDV ELISA. For ear notching calves, a medium pig ear-notcher works best if used on the lower aspect of the ear where the notch can be seen from a distance yet does not affect the function or the ear flap. If sending an ear notch DO NOT place in formalin, simply place in a labelled zip lock bag, freeze and send to lab.
Since an acute infection can result in the production of viral antigens over a short period of time, a BVDV-positive result in the ELISA may not always be indicative of a persistently infected animal. A definitive diagnosis that a particular animal is persistently infected should only be made after a second sample is taken at least three weeks after the initial sample and the second sample ia also found to be BVDV-positive.
Test Method: ELISA
Sample Requirement: serum or ear notch
Lab Testing Time: Same day