Silica Urolithiasis In Beef Cattle: I. Observation On Its Occurrence.

Urolithiasis is the term used to denote the formation of urinary calculi in animals including disease conditions that arise as a direct result. The terms urinary calculus and urolith on the other hand apply only to the actual calculi or uroliths formed in urolithiasis. In cattle, urinary calculi present in the bladder, on occasions enter and obstruct the urethra. This is the common form of obstructive urolithiasis in steers and bulls. The severity of the condition is due to the fact that when urethral obstruction is complete as it often is, urine in the bladder does not have normal exit. Regardless of the obstruction, excreted urine continues to be passed into the bladder with the result that barring surgical intervention, bladder rupture (occasionally urethal rupture ensues. In cattle, bladder rupture is virtually one hundred percent fatal. The mechanism of obstructive urolithiasis and its importance in cattle is described in more detail below. Urolithiasis in cattle is not always obstructive. In the greater majority of cattle with urolithiasis it exists without producing observed clinical manifestations and is discovered only after post mortem examination. It would appear, that, under the condition of the present studies, clinical urolithiasis is merely a function of the incidence and prevalence of a much more extensive subclinical urolithiasis in the cattle population. Therefore, in this paper the unmodified term "urolithiasis" is used with