Abstract
Amoxicillin(2S, 5R, 6R)-6-[(R)-(-)-2-Amino-2-(p-hydroxyphenyl)acetamido]-3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo 3.2.0 heptane-2-carboxylic acid trihydrate)is a penicillin class antibiotic and efficacious against Pasteurella piscicida infection of cultured yellowtail(Seriola quinqueradiata). This study was carried out to investigate toxicity of amoxicillin at doses of 80mg/kg B.W. and 400mg/kg B.W. for 10 days administration in young yellowtail(about 100g body weight). The toxicity was evaluated by appetite, abnormal movement, growth, external and internal views, hematology and histopathology. The fish administered at a dose of 400mg/kg B.W. showed no abnormality of appetite, movement, external and internal views and hematology excepting increased erythrophagocytosis of splenic macrophages. Results obtaind in this study indicated that doses under 400mg/kg B.W. of amoxicillin was safe for young yellowtail.
