Urethral Leiomyoma Complicated with Lower Urinary Tract Obstruction in a Dog

An 11-year-old, intact female Shihtzu showing anuria was diagnosed as a urethral leiomyoma. The tumor occupied and obstructed the urethral lumen. In this report, the urethral tumor and secondary obstruction could be diagnosed via ultrasonography and contrast study such as excretory urography and voiding urethrography. Ultrasonography revealed a hypoechoic, demarcated urethral mass in proximal urethra. Contrast study confirmed the urethral obstruction and ruled out the expansion of the tumor into the urinary bladder. The clinical signs of the dog were completely resolved after removing the urethral mass and urethral anastomosis. Leiomyoma is a benign smooth muscle tumor, and rarely reported in lower urinary tract.