Intestinal changes in gnotobiotic piglets experimentally inoculated with porcine rotavirus.

Intestinal lesions were studied in 8 gnotobiotic piglets orally given porcine rotavirus by light microscopy, scanning electron microscopy and transmission electron microscopy. Five of these piglets were killed 6, 12, 18, 24 and 48 hours after inoculation, respectively. Of the other 3 piglets, one died 60 hours and two became moribund 96 and 114 hours after inoculation, respectively. All the infected piglets showed diarrhea between 18 and 24 hours after inoculation. Examination of the small intestine by light microscopy and scanning electron microscopy indicated the extensive degeneration and desquamation of epithelial cells with villi stripped and shortened. Villous degeneration, especially that in the jejunum and ileum, was very severe 24 hours after inoculation. Within 48 hours after inoculation, all the stripped villi were replaced by multiplication of regenerated cuboidal epithelial cells. Transmission electron microscopy revealed many virus particles in the epithelial cells of the small intestine 18 hours after inoculation.