[1] Seoul Natl Univ, Coll Vet Med, Dept Vet Pathol, Suwon 441744, South Korea
[2] Seoul Natl Univ, Coll Vet Med, Dept Theriogenol, Suwon 441744, South Korea
[3] Seoul Natl Univ, Coll Vet Med, Dept Virol, Suwon 441744, South Korea
[4] Seoul Natl Univ, Coll Vet Med, Dept Infect Dis, Suwon 441744, South Korea
[5] Seoul Natl Univ, Coll Vet Med, Dept Parasitol, Suwon 441744, South Korea
[6] Natl Vet Res & Quarantine Serv, Anyang, South Korea