Ureter
The ureters are muscular tubes approximately 70 cm long that transport urine from each kidney to the bladder via peristaltic contractions. They enter the bladder at an oblique angle, creating a valve-like mechanism that prevents urine reflux. The urinary tract also includes the kidneys, bladder, and urethra. Equine urine is normally turbid and mucoid due to calcium carbonate crystals.
Ureteral calculi or obstruction can cause colic-like signs and azotemia. Diagnosis uses ultrasound and bloodwork. Relevant in evaluations of urinary tract disease and after trauma.
## Overview Ureteral obstruction is blockage of the tube carrying urine from the kidney to the bladder, usually by a stone. It causes colic and hydronephrosis (swelling of the kidney) visible on ultr
## Overview An ectopic ureter is a congenital abnormality in which the ureter opens in an abnormal location, bypassing normal sphincter control. Affected horses, usually fillies, show continuous urin
## Overview Ureterolithiasis is the presence of stones lodged in the ureter. Stones cause flank pain, blood in the urine, and hydronephrosis. They are less common than bladder stones but more difficu
Changes in urine volume, color, or consistency, or signs of straining, should be evaluated. Normal equine urine is often cloudy.
## Overview Ureteral obstruction is blockage of the tube carrying urine from the kidney to the bladder, usually by a stone. It causes colic and hydronephrosis (swelling of the kidney) visible on ultrasound. Unilateral obstruction may be asymptomatic if the other kidney compensates. ## Causes Ureterolith (stone) or less commonly stricture or blood clot. ## Diagnosis Ultrasound showing hydronephrosis and sometimes the stone. Bloodwork assesses overall kidney function. ## Treatment Surgical removal or bypass in selected cases. Medical management of pain. Prognosis depends on remaining kidney function. ## Recovery and Prognosis Guarded if the kidney is severely damaged. Better if obstruction is relieved early. ## Prevention None proven. Signs include: colic; hydronephrosis on ultrasound; may be asymptomatic if unilateral
## Overview An ectopic ureter is a congenital abnormality in which the ureter opens in an abnormal location, bypassing normal sphincter control. Affected horses, usually fillies, show continuous urine dribbling from birth, perineal scalding, and recurrent urinary tract infections. ## Causes Developmental malformation of the ureteral opening. ## Diagnosis Clinical signs from birth, endoscopy, contrast studies, or computed tomography demonstrating the abnormal termination. ## Treatment Surgical correction (ureteral reimplantation or nephrectomy in unilateral cases) when feasible. ## Recovery and Prognosis Good with successful surgery. Uncorrected cases suffer ongoing incontinence and infection. ## Prevention None (congenital). Signs include: continuous urine dribbling from birth; perineal scalding; recurrent urinary tract infections
## Overview Ureterolithiasis is the presence of stones lodged in the ureter. Stones cause flank pain, blood in the urine, and hydronephrosis. They are less common than bladder stones but more difficult to manage because of their location. ## Causes Mineral precipitation, usually calcium carbonate. ## Diagnosis Ultrasound, urinalysis showing blood, and sometimes contrast studies. ## Treatment Surgical removal when accessible. Lithotripsy is rarely available. Prognosis is guarded. ## Recovery and Prognosis Guarded. ## Prevention None specific. Signs include: flank pain; blood in urine; hydronephrosis
Ureteral calculi or obstruction can cause colic-like signs and azotemia. Diagnosis uses ultrasound and bloodwork. Relevant in evaluations of urinary tract disease and after trauma.
Changes in urine volume, color, or consistency, or signs of straining, should be evaluated. Normal equine urine is often cloudy.
See the Ureters & Urinary Tract on our interactive 3D horse model. Open 3D Model