outbreak of redmouth disease among cultured fresh water fishes in Ismailia governorate

A severe outreak of redmouth disease in a fish farm located at Ismailia governorate involved 30% and 40% mortality rates in both Oreochromis niloticus and Cyprinus carpio fishes. A total of 30 clinically diseased fishes were examined for the presence of the major causative pathogen. Aeromonas hydrophila was recoverted from all the examined cases. Intraperintoneal inoculation of A. hydrophila was carried out in 40 apparently healthy fish of both spieces and re-isolation of the pathogen was done after the clinical signs postmortem lesion were observed. Treatment of the diseased fish was carried out after using the disc diffusion technique with oxytetracycline which gave good results