EFFECTS OF THE INTESTINAL FLAGELLATE, COCHLOSOMA-ANATIS, ON INTESTINAL MUCOSAL MORPHOLOGY AND DISACCHARIDASE ACTIVITY IN MUSCOVY DUCKLINGS

Newly hatched female Muscovy ducklings were randomly separated into 2 groups of 12 and 1 group of 13, Ducklings in the first 2 groups were e ach orally inoculated with 0.5 ml of sterile normal saline containing 0 and 3 x 10(6) trophozoites of Cochlosoma anatis, respectively. Birds in the third group were each orally inoculated with 3 x 10(6) trophoz oites for 5 consecutive days. Birds were weighed daily for the first 5 days and then on days 7, 14 and 21 post-inoculation (p.i.). On days 6 , 7, 8, 13, 14, 15, 20, 21 and 22 p.i., 1 bird from each group was kil led and samples of intestine at 7 levels-were taken for trophozoite co unts, mucosal disaccharidase analyses and morphometric analysis. Body weights did not differ among treatment groups at any time during the e xperiment, Trophozoite numbers did not change over the period 6-22 day s p.i. Trophozoite numbers were lowest in the anterior small intestine and increased distally, but very few were observed in the caecum. Cry pt depth was greater in all regions of the small intestine in inoculat ed groups compared to uninoculated controls, and was significantly inc reased in the duodenum, proximal jejunum and mid-jejunum (P<0.05). Vil lus height was greater in inoculated groups compared to controls at al l levels of the intestine and was significantly increased in the duode num, proximal jejunum and ileum (P<0.05). Mucosal palatinase and malta se activity in the small intestine were reduced in inoculated groups c ompared to uninoculated controls; palatinase activities were significa ntly reduced in the proximal and mid-jejunum and maltase activities we re significantly reduced in the mid-jejunum (P<0.05). Sucrase activiti es were significantly increased at all levels of the small intestine i n inoculated ducklings compared to uninoculated controls (P<0.05). Alt hough no clinical signs were evident, Cochlosoma infection significant ly altered intestinal morphometrics and mucosal enzyme concentrations in ducklings, in several cases in a counter-intuitive direction. Copyr ight (C) 1996 Australian Society for Parasitology. Published by Elsevi er Science Ltd.