[Variability in the localization of cryptosporidia in the intestines of spontaneously infected calves].

31 to 37 localities were examined in the small and large intestines of 48 calves spontaneously infected with cryptosporidiosis. It was found that cryptosporidia occurred the most frequently in the distal part of small intestine, within the range of six metres of small intestine, in front of the ostium ileocecale (OIC); at the ileocecal valve the incidence of cryptosporidia dropped rapidly. In none case were the protozoans revealed in duodenum and in the adjacent four to six metres of proximal jejunum. The small intestine was invaded by cryptosporidia in a variable manner, in some cases a major part was continuously invaded, in other cases only one or two metres of distal jejunum without any changes in the ileum and vice versa. Approximately half the calves had cryptosporidia in the cecum, fewer cryptosporidia were found in the transverse colon. Cryptosporidia in the rectum were found in about 25% of cases. Some calves had cryptosporidia only in the large intestine. The intensity of the mucous membrane invasion varied: mass incidence of cryptosporidia was found only in caudal parts of small intestine, with high variability of the extent and with sudden cases of negative findings. In the large intestine only the cecum was invaded more intensively and in a diffusive manner, in the transverse colon and in the rectum the groups of parasites were usually found at the openings and in the wall of Lieberk uhn 's crypts.