Fetotoxicity of some anticoccidial drugs in chickens.

Fetotoxic effects induced by three anticoccidial drugs: robenidine, salinomycin and arprinocid were elucidated in the chicken. Different doses of these drugs were inoculated in groups of embryonated chicken eggs by the yolk sac route. After inoculation, candling of the eggs was performed daily and embryonic or fetal mortalities were recorded. At 19 days old, alive fetuses were collected, weighed, measured and examined morphologically for abnormalities. A group of eggs was kept non-inoculated as a control and another was inoculated with the solvent of the tested drugs. Inoculation of 0.09-9.75 mg robenidine/egg, 0.06-6.75 mg salinomycin/egg or 0.08-8.25 mg arprinocid/egg into the yolk sac of 7 days old embryos caused a dose-dependent fetal death. Arprinocid was the most lethal to chicken fetuses, followed by salinomycin while robenidine was the least. Dead fetuses were usually haemorrhagic, dwarfish and friable. Surviving fetuses showed a dose-dependent reduction in body weight and length, insignificant decrease in leg and wing lengths as well as some developmental abnormalities.