Jeremy Van Boening, BS Bovine Virus Diarrhea (BVD) is one of the most significant viral infections of cattle. BVD was first recognized as a disease syndrome in 1946. Today, 70 to 90 percent of the world's cattle population is seropositive for BVD. 1 There are at least two genotypes, type 1 and type 2; and two biotypes, cytopathic and noncytopathic. Both type 1 and type 2 genotypes have cytopathic and noncytopathic biotypes as members; and both type 1 and type 2 genotypes have many different strains, some of which are more deadly than others.2 Recently, the type 2 genotype has caused many of the most severe cases of BVD.3,1,4