Ultrasonography of the ureters.

It is difficult to visualize the normal canine or feline ureters ultrasonographically; however, diagnosis of various abnormalities associated with ureteral dilation is possible in many instances. Ultrasonography is a practical method for diagnosis of ectopic ureter, ureterocele, and certain causes of ureteral obstruction that compares favorably with contrast radiography because it is quicker, does not involve use of contrast media or ionizing radiation, and usually requires no sedation or anesthesia. Ultrasonography is a convenient method for examining adjacent organs, principally the kidneys and bladder, that may be affected in animals with ureteral abnormalities. Also, ultrasound guidance facilitates certain interventional diagnostic procedures for the ureters.