Impact of dietary spray-dried bovine plasma addition on pigs infected with porcine epidemic diarrhea virus

Duffy, Mark A; Chen, Qi; Zhang, Jianqiang; Halbur, Patrick G; Opriessnig, Tanja

On dpi 14, all pigs were killed by intravenous pentobarbital overdose (FATAL-PLUS, Vortech Pharmaceuticals Ltd, Dearborn, MI) and necropsied. Tissues collected from pigs at necropsy included eight sections of small intestines, three sections of large intestine, and one section of mesenteric lymph node. Tissues were immediately put in 10% buffered formalin and routinely processed for histopathology and assessed for lesions by a veterinary pathologist blinded to the treatment status. Presence and degree of atrophic enteritis were scored ranging from 0 = normal to 3 = severe. To determine presence and amount of PEDV antigen in tissue sections, a PEDV immunohistochemical stain was performed on intestines from all pigs as described (Stevenson et al., 2013) . The amount of PEDV antigen was scored by a veterinary pathologist blinded to the treatment status with 0 = no signal, 1 = 1% to 10% staining, 2 = 11% to 50% staining, and 3 = greater than 50% staining.