Sixty swabs from freshly dead rabbits 3-4 week old (20 cloacae, 20 mouth and 20 nasals) were collected for bacteriological examination. Out of 60 examined samples 33 (55%) were positive for bacteria distributed (16 cloacae, 5 mouth and 12 nasal) in single 28.33% (17) and mixed 26.67 (16) isolates, the main isolated bacteria was E. coli. Antibiogram study revealed that amoxicillin was the most effective drug antibiotic against isolated E. coli. A total of 60 healthy balady rabbits, 3-4 week old proved that free from E. coli infection were divided into 4 equal groups (15 each), 1^st group healthy rabbits kept as control group, 2^ndgroup healthy rabbits treated with 25mg amoxicillin/kg b.wt once daily for 5 consecutive days in drinking water, 3^rd and 4^th group were experimentally infected with E. coli was done at 21^th day, 3^rd group was infected rabbits non treated and 4^th group infected rabbits treated with 25mg amoxicillin/kg b.wt once daily for 5 consecutive days in drinking water. Clinical signs and mortality rate, body weight gain and feed conversion rate, were recorded.  Effect of Amoxicillin and infection in leukogram and biochemical parameters was studied. Amoxicillin residue in breast muscle, liver and kidneys were detected.
Infected rabbits with E. coli showed clinical sign such as depression, weakness, illness, dullness, sneezing, off food, rough fur, and diarrhoea and 26.7% mortalities.
Healthy rabbits treated with 25mg amoxicillin / kg bwt.  displayed a significant increase in body weight gain, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase, urea and creatinine beside decrease feed conversion rate, insignificant increase in leukocytes, neutrophils, basophils, eosinophils, monocytes, lymphocytes and albumin /globulin ratio beside insignificant increase in total protein, albumin and globulin
Infected rabbits with E. coli showed significant decrease in weight gain, neutrophils, total protein, albumin and globulin beside significant increase in feed conversion rate, leukocytic count, lymphocyte monocyte, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase, urea and creatinine coupled with insignificant increase basophils and eosinophils.
Amoxicillin residues in breast muscle, liver and kidney in both healthy and diseased rabbits were high at 1^st day of clearance period and completely disappeared at 7^th days of clearance period. High amoxicillin residue was found in kidney followed by liver and lowest residues were detected in breast muscle.
It could concluded that, E. coli infection in rabbits resulted in adverse effect in body weight, hemato-biochemical parameters, amoxicillin treatment rabbits improved these parameters.