Histopathological survey on Salinomycin toxicity inbroiler chickens infected by experimental coccidiosis

Coccidiosis is a signifcant problem in the industrial poultry raising systems and several drugs are being used in order to prevent and treat this problem. Ionophores are the most common anticoccidials drug. Salinomycin has an extreme use in Iran poultry industry as a coccidiostat drug, this study has been performed to evaluate toxicity effects of its overdoses in broiler chickens infected by experimental coccidiosis on the basis of histopathological fndings. 50 female Cobb-500 day-old chicks randomly divided in 5 groups (control positive, control negative and treatment 1, 2 and 3). All chickens were infected by Eimeria strains included 25% E.tenella, 40% E.maxima, 20% E.acervulina and 15% E.necatrix in oral administration of 100 (equal to 10000 Oocysts). Control positive group was received preventing dose of Salinomycin (75 ppm). Chickens in treatment groups 1, 2 and 3 received 150, 300 and 600 ppm of drug respectively and in negative control group no drug was added after contamination. During the study, external symptoms and necropsy fndings were exactly evaluated. The tissue samples were fxed in neutral buffered 10% formalin, routinely embedded in paraffn and stained with H&E. Results indicated that higher doses (up to 75 ppm) of Salinomycin increase depression and paralysis. Toxicated chickens were depressed and muscles atrophy, falling down of wings and neck and also green diarrhea were observed obviously. Macroscopic examination confrmed that enhancement the dose of Salinomycin signifcantly prevent intestinal villi and mucous destruction due to Eimeria invasion, but influence growing performance considerably. Acute Cell Swelling (ACS) in proximal tubules and Acute Tubular Necrosis (ATN) were obvious pathologic fndings in kidneys. Microscopic fndings indicate congestion and hemorrhage in the majority of tissues with necrosis and accumulation of inflammatory cells.