High risk contact includes: commingling your breeding herd with stocker cattle, fenceline contact with purchased stocker cattle and fenceline contact with suspect herds.

About 7% of cow-calf herds in the U.S. contain at least one and often many PI animals. Herds with no or inconsistent BVD vaccination programs, herds that import large numbers of untested cattle (especially pregnant cattle), and herds with a history of high disease rates and poor reproductive performance are at higher risk than herds with well managed BVD control strategies. In infected herds, young calves are more likely to be PI compared to older animals. Even fenceline exposure to these high risk herds may increase the chances of introducing BVD into your herd.

Purchased groups of stocker cattle typically consist of cattle from many different cow-calf herds. Although very few individual calves are PI, when commingeled we expect 1-2 of every 500 stocker calves to be PI. Therefore, when exposing the mature cow herd to large numbers of stockers, the risk of exposure to BVD virus is relatively high. Some of the stockers may also be transiently infected with BVD virus, but this typically doesn't last for a long period of time and is often associated with other signs of illness, (respiratory disease) in the stocker calves.

Although exposure to cattle harboring BVD may be unavoidable, there are some strategies to limit the damage caused by the virus. Limiting exposure of pregnant cows to outside cattle until pregnancies are at least 150 days of gestation minimizes the chances of creating new PIs in the herd. Fenceline exposure is not as risky as mixing pregnant cattle with animals at high risk for harboring BVD in the same pasture or housing area.