MORPHOLOGICAL-CHANGES IN THE JEJUNUM OF CALVES NATURALLY INFECTED WITH GIARDIA SPP AND CRYPTOSPORIDIUM SPP

Giardiosis and cryptosporidiosis are frequently diagnosed in calves at the large animal clinic of the veterinary school. Few studies have be en reported in the literature regarding pathogenesis of these two inte stinal protozoa. The aims of this study were to follow the histologica l changes in the villi and crypts and the changes in the number of int raepithelial lymphocytes in the jejunum of naturally infected calves d uring the acute phase of infection. For this purpose, 29 calves aged b etween 7 and 10 days were bought at a local auction. The animals were housed in individual pens to avoid cross-contamination. Fecal samples were examined microscopically for the presence of Giardia cysts and Cr yptosporidium oocysts, three times per week for a period of 45 days. S ix calves did not pass any cysts or oocysts and were used as controls. Fifteen calves passed Giardia cysts only. five passed both cysts and oocysts, and three passed oocysts only. The villus to crypt ratio inde x was 1.76 in the control group and 1.08 in the Giardia-infected group . In the Cryptosporidium-infected calves, the ratio was 1.18 and calve s infected with both parasites had an index of 1.37. The number of int raepithelial lymphocytes per millimeter of jejunum tissue was 21 in th e control group. This number was doubled in the calves infected with G iardia, but was slightly lower in the other infected groups. All of th e infected carves had intermittent diarrhea and mucus was seen in many fecal samples. (C) 1997 Elsevier Science B.V.