Pathology Of The Acute Toxicity, Accumulative Toxicity And Chronic Toxicity Of Azithromycin In Experimental Chickens

Dafa black bone egg chickens in this experiment were used with the objects of studying on pathology of the acute toxicity,the cumulative toxicity and the chronic toxicity of azithromycin. In the acute toxicity experiment,the chickens were affected with feeding a dose of azithromycin. The half lethal dose(LD₅₀ )was 4.57g/kg per body weight,the confidence limit 0.66±0.055 and the confidence interval 4.03⁵.19g/kg of 95% by Karber method. The results showed that azithromycin had low toxic response.The affected birds showed significant clinic symptom in 20 minutes after given azithromycin,which included low spirit, decompensation, inappetence.The more dose,the earlier and severer the clinic symptom.At necropsy, livers welled with yellow.Also lungs and kidneys were swelled . Histopathologically, degeneration appeared in the heart,the liver and the kidney.In the accumulative toxicity experiment, The chickens were affected with feeding a fixed dose of azithromycin (1/5LD₅₀) . The accumulation coefficients was 2.79.The result showed that azithromycin had distinct accumulation.The clinic symptom and histopathological changes were similar to those of the acute toxicity.Haematologically, the serum total protein contents, albumin contents,A/G contents were much lower and the serum globulin contents,total cholesterin contents,alanine aminotransferase activities,aspartate aminotransferase activities, lactate dehydrogenase activities, alkaline phospatase activities and blood sugar contents were much higher in the accumulative toxicity groups than in the control group. In the chronic toxicity experiment, the chickens were affected with feeding a fixed dose of azithromycin (1/20LD₅₀, 1/40LD₅₀, 1/80LD₅₀) . Clinic symptoms of the affected birds were not obvious as those in the acute toxicity experiment. Haematologically, the serum total protein contents was much lower in prophase while it was much higher in anaphase than control group.The serum albumin contents were much lower than those in control group.The serum globulin contents , total cholesterin contents,alanine aminotransferase activities,aspartate aminotransferase activities,lactate dehydrogenase activities,alkaline phospatase activities and blood sugar contents were higher in toxic groups than in control group,as same as the changes in the accumulative toxicity experiment.