Testis of pigeon (Columba livia domestica) exposed to Thiram at 10 mg/Kg/day after 10 weeks (H&E. Magnification x10 and x40). L, lumen; Sp, spermatozoa; SG, spermatogonia; SC, spermatocyte; SD, spermatide; S, Sertoli cells. Acute degenerative in the histoarchitecture of testis characterized by elongated and irregular diameter of seminiferous tubules with all the successive stages of spermatogenesis. Deteriorating of Sertoli cells, a pronounced decrease in interstitial space and severe atrophy of Leydig cells.