According to Bruce Hoffman, veterinarian and president of Animal Profiling International, while some Persistently Infected (PI) animals may look like they are in poor health, most look completely normal. The only way to identify PIs is by a diagnostic test. Taking a small ear notch is all that is needed. Producers can take the sample themselves, and should work with their veterinarian to determine how the sample should be stored and shipped.
To manage bovine viral diarrhea (BVD) in a herd, it is important to utilize vaccinations, testing to identify PIs, and biosecurity measures. A herd vaccination should always be the first line of defense against the BVD virus. A PI testing and surveillance plan should be initiated if the herd is a high-risk herd, defined as a herd experiencing reproduction and/or health problems. Herds that are in expansion mode are also at high risk. If a PI calf is identified, a sample should be taken from the dam. Simple PCR string/bulk milk tank samples can identify if a PI is present in the milking string. Producers should also plan to purchase animals that are BVD PI negative and test animals on arrival to ensure PIs do not enter the herd.
For more information about BVD identification and management, please contact Bruce Hoffman at firstname.lastname@example.org.