Uroperitoneum and bilateral renal rupture in a buck following urethral and urinary bladder obstruction due to carbonate apatite/struvite urolithiasis

Urolithiasis is encountered less frequent in goats compared to other ruminants. When followed by lower urinary tract obstruction, it may, if not diagnosed and treated early, lead to urethral or bladder rupture, azotaemia and death. We describe a case of obstructive carbonate apatite/struvite urolithiasis in a buck, causing complete urethral and bladder blockage followed by bilateral renal rupture and uroperitoneum. A buck from a herd from Asvestohori, Thessaloniki, was presented in May 2011 with a history of dysuria that had progressed to anuria. The other buck of the herd showed similar signs albeit to a smaller degree. The animals were fed straw, alfalfa hay, and commercial concentrates, and were allowed to graze for a few hours daily. The last two months the water supplied to the animals came from a well within the farm compounds. On necropsy, perineal erythema, severe abdominal distention due to severe uroperitoneum and bilateral renal rupture were noted. A large number of spherical smooth olive-green stones 1mm-1.5cm in diameter were present in the bladder and urethra, causing their complete obstruction, severe distention of the bladder, and heamorrhagic content throughout the urethral lumen. Bacterial culture of urethral samples in aerobic conditions was negative. Chemical analysis showed that the uroliths were composed of struvite (40%) and carbonate apatite (60%). Conclusions Urolithiasis in the buck may be due to carbonate apatite-struvite uroliths. Bilateral renal rupture due to obstructive urolithiasis is rarely reported in the goat.