Testing for Persistently Infected BVD Animals 

Dairy or beef cattle herds can now be screened for persistently infected BVD animals at the ADDL. The test involves cell culture virus isolation in a 96 well microtiter plate followed by detection of positives with an immunoperoxidase monolayer assay.

 Animals to be tested should be at least 3 months old. By this age, maternal antibody should no longer be an inhibitory factor in the isolation procedure.

 To interpret results accurately it is important to remember that a positive result from a single sample could be due to an acute or a persistent infection. The persistently infected or carrier animal should also be positive if a second sample, drawn three weeks later, is tested.

 The test is not now being performed on a regular basis, but please notify the laboratory prior to submission of serums for this procedure.

 - by Mary Woodruff, Professional - Medical Assistant