[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Prevent Vet Med & Anim Hlth, Ave Prof Orlando Marques de Paiva 87, BR-05508270 Sao Paulo, SP, Brazil
[2] North Carolina State Univ, Coll Vet Med, Dept Populat Hlth & Pathobiol, 1060 William Moore Dr, Raleigh, NC 27607 USA