Effects of furazolidone in the early chick embryo

Effects of furazolidone in early chick embryos were investigated in order to determine the feasibility of using this biological system as a model for studying the mechanism(s) of furazolidone toxicity. Double and triple injections of varying dosages of furazolidone were administered via the yolk sac at early stages of incubation. Toxic levels of the drug affecting both growth and levels of glycogen were dosage-dependent and time-dependent. Double injections of furazolidone at a dose as little as 60 microgram/egg administered at 40 and 72 hr of incubation significantly retarded growth (P less than .001) and increased glycogen levels (P less than .05) in the embryo and yolk sac. Mortality was high in embryos receiving toxic levels of furazolidone, but no gross abnormalities were observed.