Clinical, ultrasonographic and pathological description of bladder distension with consequent hydroureters, severe hydronephrosis and perirenal fluid accumulation in two rams putatively ascribed to pelvic nerve dysfunction

Marked urinary bladder distension, hydroureters, severe bilateral hydronephrosis, and perirenal fluid accumulation were identified ultrasonographically in two rams from the same farm but separated by 24 months' interval. Both rams were observed to urinate but the flow rate of urine was estimated to be less than normal and the duration was reduced to around 5-10 s when around 20-30 s is considered normal. There was normal tail and rectal muscle tone, and normal perineal and pelvic limb reflexes. A presumptive diagnosis of pelvic nerve dysfunction causing detrusor atony and bladder distension with secondary pressure-induced hydronephrosis is suggested but unproven. Detailed dissection at necrospy found no evidence of urethral obstruction.