Coinfection Associated with Naturally Occurring Cryptosporidiosis in Broilers

Summary The clinical and laboratory findings associated with Cryptosporidium infection in four broiler flocks were reported. The severity of Cryptosporidium-induced disease is greatly compounded by the presence of other pathogens. Tracheal swab culture on blood agar revealed a bacterium, which identified as Ornithobacterium rhinotracheale by further biochemical and serological characteristics. This isolate was resistant to enrofloxacin and flumequine, and sensitive to ampicillin and tiamulin. Escherichia coli isolated from heart of the carcasses was resistant to all conventional antibiotics. Eimeria tenella was also detected in the ceca of some carcasses of this flock. Simultaneous isolation of C.baileyi, Clostridium perfringens type A, and E. coli serogroup O8 in a broiler flock affected by gangrenous dermatitis and serious weight gain loss was also reported.