The in vitro antibacterial activity of enrofloxacin and amoxycillin was evaluated against Aeromonas hyDROPhila pathogen. Also, the in vivo efficacy of both drugs was investigated on Oreochromis niloticus fish experimentally infected with Aeromonas hyDROPhadministration at their therapeutic dose levels (10 mg I kg b.wt I day) and(80 mg I kg b.wt I day) for 10 successive days, respectively. The obtained results indicated. that both enrofloxacin and amoxycillin were effective invitro and in vivo against Aeromonas hyDROPhila micro-organism withMIC of (0.012) ug/ml for enrofloxacin and (0.4) ug/ml for amoxycillin,indicating high antibacterial activity of both drugs. It was found that thenumbers of dead fish in the groups administered enrofloxacin and loramoxycillin were significantly lower than that in control group and themortality in infected group was (83.33%) while in the infected and treated groups with enrofloxacin and amoxycillin were (10%) and (16.66%)respectively. Enrofloxacin and amoxycillin residues in liver, kidney and muscles of Oreochromis niloticus were determined after administration oftheir recommended therapeutic doses orally for ten successive days. Thehighest concentration of enrofloxacin was found in kidney than liver andmuscles. Enrofloxacin residues in liver disappeared on the 1 th day, inmuscles disappeared on the 13th day while in kidney disappeared on theI-Anatomical studies (cross and sagittal sections) were applied on fivegoats.If-Normal sonographic images of different abdominal organs in sheepand goats .These images were performed on (300) apparently healthysheep and goatsIII-Sonographic Images of some surgical affections of the abdomen”clinical cases” were diagnosed in (195) small ruminants, (95) sheep and(100) goats.I-normal sonographic Images of different abdominal organsin sheep and goats1- The liver of sheep and goats was examined in standing or lateralrecumbency on the right side from ih to 1 z” intercostal spaces using 3.5/5MHz and appeared as numerous weak echoes homogenously distributedwith its blood vessels. The portal vein appeared with an echo genic wallwhile the hepatic vein had a less echogenic one. 2- The gall bladder wasexamined in standing or lateral recumbency on the right side at 9th and or Subgroup I was given isoniazid and rifamycin, subgroup II was givenpyrazinamide and rifamycin and subgroup III was given isoniazid andpyrazinamide. All the three subgroups were given the drugs twice weeklyfor 60 days. One blood sample of about 1 ml was collected from the earvein on EDT A as enticoagulant for complete blood picture, another bloodsample of about 5 ml was collected from the ear vein and left to clot forserum separation to perform the biochemical analysis. The time of bloodsampling was performed after 15,30,60 and 90 days from the beginning ofthe experiment. Erythron mass showed no significant changes comparedwith the control group in the treated group after 15 and 30 days oftreatment. Subgroup III showed hemolytic anemia after 60 and 90 dayspost administration of the drugs.