Abstract
The ciliate fauna and the bacterial flora excreted in feces of 60 race-horses belonging to Japan Racing Association were surveyed. The results obtained were as follows: (1) Seven classes of ciliate protozoa including 49 species belonging to 22 genera, were identified. Of them, 5 species were newly recorded in Japan. (2) Average number of the ciliates was 9.03×104/ml. No difference of the value among the host ages (2-6 years old) was recognized. (3) Average number of the ciliate species was 21. No difference of the value among the host ages was also recognized. (4) Efficient correlation (P < 0.001) was recognized between the incidence and the number of both ciliate genera and species. So the ciliates occurring in high population density tended to distribute widely among horses. (5) Average number of total bacterial count was 1.23×1010/ml, and gram-negative rods were most predominant, followed by gram-positive cocci.