ABSTRACT
Bacteriological results indicated that E. coli was the most important pathogen isolated in calves environment in examined farm in percentage of 47.7%. Soil and water intended for drinking of calves represent an important reservoir for the potential pathogenic agents that causing pneumonia in buffalo-calves. Infection to other calves, appears to both spread mainly through the attendant's h and s and aerosol droplets, on the other h and, E. coli and P. multocida [mixed infection] appears the more important cause of pneumonia outbreak in buffalo-calves in examined farm as they were isolated in highest percentage [47.6%] followed by the P. multocida and E. coli in percentage 28.6 and 14.3% respectively. Therefore, appears that, the association between cold, damp weather conditions and pneumonia outbreak in calves is entirely due to an increased challenge from the environmental pathogens rather than reduction in calf's resistance