Coccidiosis in the Gallbladder of a Goat

Cocciodiosis, probably due to Eimeria sp., was found in the gallbladder of a goat. Meronts, gamonts, and oocysts were found in the epithelium of villous and submucosal glands. Meronts were 11.7 x 7.7 /^m and contained 3-20 merozoites; merozoites were 8-12 ^im long and 1.5-2.3 /urn wide. Macrogamonts and unsporulated oocysts were 9.6 x 8.7 /um and 11.6 x 9.5 ^m, respectively. There was generalized cholecystitis characterized by necrosis and infiltration by mononuclear cells. Liver was normal. Several species of Eimeria parasitize the intestines of goats, sheep, and cattle, but none is known to invade the gallbladder (Levine, 1973; Lima, 1980). This report describes severe coccidiosis in the gallbladder of a dairy goat. Materials and Methods The goat was a 118-day-old purebred Alpine female from a commercial goat dairy in Darby, Montana and had been fed 50,000 sporocysts of Sarcocystis capracanis 33 days prior to necropsy. The goat showed clinical signs of acute sarcocystosis between 23 and 30 days postinoculation (Dubey et al., 1981). The goat was killed by electrocution, exsanguinated, and necropsied immediately. Portions of gallbladder and other tissues were fixed in 10% neutral-buffered formalin (NBF). A small piece of the gallbladder was also fixed in Helly's fixative. Paraffin-embedded sections were examined after staining with hematoxylin and eosin (HE). After finding coccidian stages in the gallbladder, several pieces of gallbladder fixed in NBF for 18 months were embedded in glycol methacrylate for light microscopy and also processed for transmission electron microscopy. Methacrylate-embedded sections were cut at 3 /um, and examined after staining with hematoxylin and eosin, Giemsa, iron-hematoxylin (IH) or periodic acid Schiff (PAS) hematoxylin. For transmission electron microscopy, sections were examined under a JEOL 100 ex microscope.