Abstract
The present study aimed to detect common bacteria and parasites associated with diarrhea in cattle farms and study the effects of health status, sex and age on their rates of detection. Fecal samples were collected from 100 cattle (70 diarrheic and 30 apparently healthy) from two dairy cattle farms located in Alexandria and Kafr El Sheikh Provinces. The obtained results revealed that the rates of isolation of E. coli, Salmonella spp., Shigella spp., Proteus spp. and Klebsiella spp. were 31, 7, 7, 16 and 11 %, respectively, while mixed infection was noticed in 23% of the examined fecal samples. It was observed that the rates of isolation of E. coli and Salmonella spp. were higher in diarrheic cattle (32.86% and 11.43%, respectively) than apparently healthy cattle (26.67% and 6.67%, respectively) and also in females more than in males. The rate of isolation of E. coli was higher in the age group (˂ 1 year) (33.33%) followed by the age group (˃ 2 years) (28.57%) and finally the age group (1-2 years) (25%) while the rate of isolation of Salmonella spp. was higher in the age group (˃ 2 years) (14.29 %) followed by the age group (˂ 1 year) (9.09%) and finally the age group (1-2 years) (8%). Serological identification of ten isolates of E. coli revealed the presence of O25 K11 (2), O111:K58, O101:K99, O78:K80, O125:K70 and 4 non-serotyped isolates while serological identification of seven isolates of Salmonella clarified the presence of S. Typhimurium (2 isolates) and S. Anatum (5 isolates). Antimicrobial sensitivity testing of E. coli isolates revealed that tested isolates were highly sensitive to Gentamycin, Cefatoxime and Marbocyl, moderately sensitive to Oxytetracycline and Spectinomycine while less sensitive to Amoxycilline + clavulanic acid and Norfloxacin while for Salmonella isolates, it was found that the tested isolates were highly sensitive to Enroflox and Marbocyl and moderately sensitive to Amoxycilline + clavulanic acid while less sensitive to Gentamycin, Cefatoxime, Tetracycline and Spectinomycine. On the other hand, the frequency distribution of enteric parasites detected in fecal samples of cattle by direct microscopic examination revealed the presence of Eimeria spp., Ascaris spp., Strongyloides spp. and Fasciola spp.at the rates of 20, 11, 8 and 7%, respectively and they were detected in a higher rate in diarrheic cattle than apparently healthy cattle. Also, the effects of sex and age groups were studied.

Key words: Diarrhea, Epidemiology, Cattle, Bacteria, Parasites,