A 5-months-old, commercial-crossbreed male lamb was remitted to post-morten study. The clinical history about of animal included: signs of severe abdominal distension, anorexia, poliaquiuria, straguria and prolonged urination posture, urine dribbling and blood-tinged urine. Necropsy revealed ascitis and a hemorrhagic fibrine membrane floating in approximately 8 litres of urine caused by a rupture of the urinary bladder in consequence of a total blockage of urethral lumen by multiple small stones localized in the sigmoid flexure of the animal. Obstructive urolithiasis is a common problem in the fed-flocks affecting between 20 % and 30 % of the animals. A diet with adequate mineral balance could reduce the health risk of formation of urinary stones.