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Clinical signs associated with urolithiasis vary based on the location and duration of the obstruction. Common clinical signs include listlessness, anorexia, colic, tail switching, posturing, vocalization (more common in goats), and dehydration. Less common signs include rectal prolapse associated with tenesmus. For urolithiasis associated with phosphate calculi, stones can be appreciated on the preputial hairs (Figure 20.1). For cases with a single obstructive urolith, careful palpation of the urethra along the length of the penis might assist with location of the urolith.

Figure 20.1 Urethral calculi visible on preputial hairs.

Acute urethral obstruction is commonly associated with acute colic symptoms such as bruxism, repeated stretching, treading of feet, and kicking of the abdomen in bulls and steers. In addition to the previously mentioned clinical signs, palpation of the preputial orifice and preputial hairs is dry, indicating no urine passage. Upon rectal palpation, affected individuals will have an enlarged urinary bladder and palpable urethral pulsations. Individuals with a partial urethral obstruction show signs of discomfort as well as dribbling of urine, stranguria, and hematuria. If a complete obstruction is left untreated for 48 hours or longer, a urethral rupture or bladder rupture will occur and signs of colic typically cease. If a urethral rupture occurs, subcutaneous edema develops along the ventral abdomen that can extend from the scrotum to the sternum, but especially in the preputial region (Figure 20.2). Severe necrosis and sloughing of these tissues can occur if left untreated. With bladder rupture, bilaterally symmetric ventral abdominal distention will occur (“waterbelly”). With bladder rupture, a palpable fluid wave will also be present. Upon rectal palpation, free abdominal fluid will be appreciable and a small partially filled urinary bladder. Bulls with uroabdomen may also develop a hydrocele. Owners typically report the colic associated with a complete urethral obstruction, then improvement for 24–48 hours, after which they notice the abdominal distention and worsening depression again. Dehydration is also severe (≥10%) with bladder rupture, due to osmotic pull of fluid from the vascular space into the abdomen. Individuals afflicted with ureteroliths and nephroliths will experience similar clinical signs as those listed above. A ureterolith and hydroureter may be palpable per rectum, but often definitive diagnosis of ureteroliths and nephroliths does not occur antemortem.

Figure 20.2 Subcutaneous peripenile swelling typically extends from the base of the scrotum cranially and involves the entire ventrum.