[1] Cornell Univ, Coll Vet Med, Dept Populat Med & Diagnost Sci, Ithaca, NY 14853 USA
[2] Univ Calif Berkeley, Sch Publ Hlth, Div Hlth Policy & Management, Berkeley, CA 94720 USA
[3] Cornell Univ, Coll Agr & Life Sci, Dept Commun, Ithaca, NY 14853 USA
[4] Univ Milan, Dipartimento Med Vet & Sci Anim, Via Univ 6, I-26900 Lodi, LO, Italy