Obstructive urolithiasis in a flock of male weaner sheep at an organised farm in semiarid Rajasthan

Obstructive urolithiasis (OU) may occur at any site but is most common at the penile sigmoid flexure in wethers and rams. Generally, single calculus causes obstruction in cattle where as, multiple calculi are common in sheep. At Central Sheep and Wool Research Institute (CSWRI), Avikanagar farm heavy incidence of urolithiasis was recorded during the months of May – July, 2004 and material from this incidence is the source material for this study. Overall incidence of urolithiasis among all the breeds was 10.35%. Breedwise, higher incidence was recorded in Garole (30.43%) followed by Bharat merino (25%), Garole X Malpura (6.77) and negligible in Malpura weaner males (0.88%). Necropsy examination revealed obstruction due to phosphatic calculi of non infectious origin located in urinary bladder, penile sigmoid flexure and kidneys. Predominant pathological lesions observed in urinary bladder, kidneys, penile urethra with, toxaemia/uroperitonitis and edema. It is concluded that during summer months lack of fiber intake and increased dependence on concentrate feed would have played a role in predisposition of obstructive urolithiasis exclusively involving such a large number of male hoggets for the first time in the history of the institute.