Ovine and Caprine Urolithiasis Study Guide

Overview and Clinical Importance

Obstructive urolithiasis is the most common urinary tract disease in small ruminants and represents a significant cause of morbidity and mortality in sheep and goats. The disease is characterized by formation of urinary calculi (uroliths) that obstruct urine flow, typically in the urethra of male animals. The condition is particularly prevalent in castrated males (wethers), pet goats, and animals on high-grain diets.

According to the USDA NAHMS study, approximately 20% of surveyed sheep operations reported at least one case of urinary calculi within a 3-year period. Early recognition and appropriate management are critical for positive outcomes, as untreated obstruction can lead to bladder rupture, urethral rupture, or death within 24-48 hours.

Etiology and Pathophysiology

Uroliths are solid crystalline formations composed of organic matrix (sugars, proteins, cells) and inorganic crystalloids (calcium, magnesium, phosphate). They form when urine becomes supersaturated with mineral components that precipitate out of solution.