Painful Micturition and/or Red Urine - Work up and Causes

Painful micturition and/or hematuria can be presenting complaints for a variety of disorders of the urinary tract. Hematuria throughout urination is consistent with hemorrhage from the kidneys, ureters, or bladder, whereas hematuria at the beginning of urination is often associated with lesions in the distal urethra. Hematuria at the end of urination is usually the result of hemorrhage from the proximal urethra or bladder neck. A thorough diagnostic evaluation, including physical examination, rectal palpation, analyses of blood and urine, endoscopy of the lower urinary tract, and ultrasonography, is usually rewarding in establishing the source and cause of urinary tract pain and hemorrhage.

Urolithiasis:
Uroliths at any level of the urinary tract may cause mucosal irritation and hemorrhage, resulting in stranguria, pollakiuria, and hematuria. The classic presenting complaint for a cystolith in a gelding is post-exercise hematuria while horses with urethroliths may have incontinence or urinary obstruction and signs of colic, often with a dropped penis. Rectal examination is usually rewarding in confirming presence of cystoliths while ure- throliths are commonly lodged at or just below the pelvic brim. Treatment of cystoliths consists of surgical removal and a variety of procedures exist.

Urinary Tract Neoplasia:
Hematuria is the most common presenting complaint for neoplasia of the kidneys, ureters, bladder, and/or urethra. Adenocarcinoma is the most common renal tumor and sqaumous cell carcinoma is the most common neoplasm of the bladder and urethra.

Exercise-associated hematuria:
Gross hematuria following exercise is a consequence of bladder mucosal erosions that are traumatically induced by abdominal contents pounding the bladder against the pelvis during exercise (often referred to as the “bongo drum bladder” in endurance horses). Although apparently non-painful to the horse, owners of affected equine athletes are often quite concerned about gross hematuria after exercise. Detection of focal bladder erosions or ulcers with a contrecoup distribution during cystoscopy with 48 hours after onset of hematuria may confirm this problem. Exercise-associated hematuria is a self limiting problem as the bladder mucosal lesions heal within a few days. […]