ULTRASTRUCTURAL ALTERATIONS IN FURAZOLIDONE-INDUCED CYSTIC TESTICULAR DEGENERATION IN DUCKLINGS

Cystic testicular degeneration was induced in groups of ducklings by feeding furazolidone at 250, 400, 550, or 750 mg per kilogram of feed (ppm) for 4 weeks. In normal ducklings, tall, columnar Sertoli cells predominated in the seminiferous epithelium. In treated ducklings, the mildest ultrastructural alteration was cytoplasmic vacuolation of Sertoli cells. In birds with more severely affected tubules, cytoplasmic vacuolation was more severe and the cells were cuboidal or rounded. The rounded cells desquamated into the tubular lumens, eventually undergoing cytolysis. In birds with the most severely affected tubules, only extensively flattened epithelial cells lined the extremely dilated seminiferous tubules. The interstitium was edematous and compacted between the expanded tubules. Many of the testicular ultrastructural alterations in furazolidone-intoxicated ducklings were similar to those described in the testicles of sodium-intoxicated cockerels.