Clostridial population and the intestinal lesions in chickens infected with Clostridium perfringens and Eimeria necatrix

Chickens infected with Clostridium perfringens and Eimeria necatrix were examined bacteriologically and pathologically. When chickens were inoculated with 1.0 x 10(8) C. perfringens and/or 2 x 10(4) E. necatrix sporulated oocysts, populations of C. perfringens in the intestinal contents were examined on 3, 5 and 7 days after E. necatrix inoculation. In both groups infected with E. necatrix, the mean clostridial counts were significantly higher than those of uninfected controls. The concurrent infection had no enhancing effects on increasing the clostridial population more than E. necatrix-alone. Mortality of 4-day-old chickens inoculated on 5 consecutive days with C.perfringens after receiving E. necatrix was higher than those of chickens inoculated with the both organisms. However, intestinal lesions of the concurrently infected group were not different from E. necatrix-alone-infected group on 5 and 7 days after the coccidial infection. When chickens received a large dose (1.5 x 10(9)) of C. perfringens after the inoculation with E. necatrix, edema in the duodenum through jejunum were observed early after the bacterial broth inoculation. These results suggest that the concurrent infection with E. necatrix and C. perfringens increases clostridial population in the intestine of the chickens and has synergic effects on mortality and edema in the upper intestine.