In O’Brien TR, editor: Radiographic diagnosis of abdominal disorders in the dog and cat, Davis, Calif, 1981, Covell Park Veterinary.) (From Park RD: Radiology of the urinary bladder and urethra. The broken line around the bladder in A and B denotes the peritoneal reflection. The bladder is ellipsoid and has a long neck, which makes the bladder appear displaced cranially from the pubis. The bladder is adjacent to the pubis and is oval. The feline urinary bladder is almost always ellipsoid (Fig. The urinary bladder in the dog is usually oval, but with distention it becomes more ellipsoid. Severe distention may occur normally if the animal has not voided owing to lack of opportunity or because of a strange or unfamiliar environment.

With extreme distention, the apex/vertex may extend to the umbilicus. The bladder is small after voiding and may not be visible radiographically. Some of these superimposition opacities can be eliminated or minimized by withholding food for 24 hours preceding the study or giving cleansing enemas, though these interventions are usually not necessary.īladder size varies with the amount of urine. Focal superimposition opacities may be created by fluid-filled small bowel, nipples, the prepuce, and cutaneous masses. Ingested material in the small bowel, fecal material in the large bowel, pelvic limb muscle, and bone from the spine and pelvis may cause superimposition opacities that obscure all or part of the urinary bladder. Emaciated or young animals may not have sufficient abdominal fat to provide good tissue contrast. Radiographic visualization of the urinary bladder is reduced by insufficient abdominal fat, inadequate distention, and superimposition opacities. The thickness of the bladder wall or mucosa cannot be identified on survey radiographs because of border effacement by urine in the lumen. The peritoneum is adherent to the serosal surface, providing a separate fourth layer. The musculomembranous urinary bladder wall consists of mucosal, submucosal, and muscular layers. Bowel (black arrows) is superimposed over the vertex of the bladder. The rectus abdominis muscle (black arrowhead) is ventral to the bladder.

The bladder neck (white arrow) is well visualized because of fat within the bladder ligaments. 39-2 Lateral radiograph of the caudal abdomen in a normal dog.

False ligament of urinary bladder