1. Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA (Flores, Del Piero, Langohr)
2. Large Animal Pathology Service, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA (Habecker)
3. Current address: Departamento de Patologia, Laboratório de Patologia Veterinária, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil (Flores)