Document Type : Original Article


1 Graduate student, School of Veterinary Medicine, Shiraz University, Shiraz, Iran

2 Department of Avian Medicine, School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran

3 Center of Comparative&experimental medicine, Basic sciences in infection diseases research center, School of medicine, Shiraz University of Medical Sciences, Shiraz, Iran

4 School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran


Nitroimidazole compounds have been traditionally used in the veterinary and human medicine, but their uses are sometimes associated with some side effects. Toxicopathological effects of nitroimidazoles have always been a major concern. There is scant information available about the pathological alterations of nitroimidazole compounds in the embryo. The objective of this study was to determine the macroscopic and microscopic lesions of metronidazole in the chicken embryo. Fertile broiler eggs were divided into two equal treatment groups as follows: group 1: saline-injected group, the eggs were injected with sterile physiological saline solution into the chorioallantoic sac. Group 2, individuals were injected with metronidazole at a dosage of 25 mg/Kg egg-weight three times into the chorioallantoic sac. Macroscopically, the embryos were stunted. The feet and wings were small and the feather formation was seriously affected. In this group, the embryos were affected by schistosomus reflexus. Microscopically, all organs were hyperemic. Based on macroscopic and microscopic findings, it is concluded that metronidazole at the above-mentioned concentration is toxic to the chicken embryo. The current study also advises caution in the extended use of nitroimidazole compounds.


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