Toxicological and biological studies on Japanese quails fed graded levels of furazolidone

Furazolidone (FZ) was administered to 42-day-old female Japanese quails as a feed additive at doses of 0, 200, 400, 600 and 800 ppm for a period of 28 days. Dose-dependent effects were observed. High levels of FZ (600 and 800 ppm) significantly altered growth, decreased feed consumption, caused marked atrophy of the ovaries and oviducts leading to cessation of egg laying, and resulted in higher mortality. Hepatotoxicity was evidenced by an increase in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase and a decrease in serum total protein, in addition to degenerative changes of the hepatocytes in FZ-treated birds. A rise in serum urea was also observed. Symptoms leading to death included a loss of appetite causing emaciation followed by nervous disturbances (compulsive movements and circling). No signs of cardiomyopathy were observed. Japanese quails did not tolerate FZ at a concentration (400 ppm) recommended for the prevention of salmonellosis in poultry.