BVD-PI Virus Testing (Ear Notch Test)
“BVD” or “Bovine Viral Diarrhea” virus causes costly reproductive problems in KY cow herds and increased sickness and death loss from pneumonia (bovine respiratory disease or “BRD”) in feeder cattle. Control of the BVD virus is through 3 equally important methods: 1) testing to identify persistently infected (“PI”) cattle, 2) vaccination and 3) biosecurity measures to reduce virus entry into the herd.
A “PI” calf is the result of a pregnant cow or heifer getting infected with the BVD virus between 42-125 days of gestation. The adult cow or heifer will experience a “transient BVD infection” which is often mild, or she may show no symptoms at all. However, the virus will also cross the placenta, infecting her unborn calf. When this calf is born, it is “persistently infected” or “PI” and is a “carrier” and “spreader” of the virus for its lifetime.
A BVD-PI calf is born with the BVD virus and sheds virus everywhere it goes for its entire life. Identification and removal of PI calves is critical to stop survival of the virus.
Testing for persistently infected (PI) animals is easy and inexpensive with the BVD ELISA test. The most commonly used sample for identifying PI cattle is an “ear notch” skin sample. Blood (serum) can also be used but not in calves less than 3 months old. If the test result is negative, that animal is negative for life and will not need testing again. Any BVD ELISA positive test result should be confirmed by separating the animal and retesting a second ear notch or blood sample drawn 3 weeks after the first sample. True PI animals will still be positive after 3 weeks while those animals with a short-term infection (transiently infected or “TI”) will test negative on the 2nd sample.
There are several laboratories in Kentucky that offer BVD PI testing as well as many veterinary practices that work with cattle. There is also a cow-side test available for use on farm.
Frequently Asked Questions on BVC-PI Virus Testing
Laboratories:
University of KY Veterinary Diagnostic Laboratory (UKVDL)
BVDV Persistent Infection Testing
Dependable Livestock Testing (Smiths Grove, KY) (They will send supplies for testing and a pre-paid box for shipping with results in 24 hours or less.)
