Infected bulls can shed virus in semen and semen quality may be altered. A susceptible cow bred by an infected bull that is shedding virus or bred artificially with infected semen may become a repeat breeder. Repeat breeding seems to be the result of failure of conception. Fertility usually returns to normal after immunity develops. As with bovine herpesvirus 1, there is no treatment for BVD virus related reproductive failure.
Control is accomplished through a good vaccination program.
Several killed and modified live virus vaccines are commercially available. The choice of a vaccine should be made by the producer in consultation with a veterinary practitioner. There are other bacteria and viruses that are known to interfere with reproduction, but the five discussed here are the most common and important threats to cattle production in Western Canada. Diagnosis of the specific cause of reproductive failure can be very difficult and requires the dedicated efforts of the producer, veterinary practitioner, laboratory veterinarians and animal nutritionists. The incidence of repeat breeding and reduced fertility are often caused by vitamin and mineral deficiencies, failure to evaluate bulls for reproductive fitness and other management factors.