Remove residual urinary bladder contents. However, in patients with lower urinary tract disease, this degree of distention may not be possible. Consequently, palpation of the urinary bladder to ensure adequate distention is necessary. Fill the lumen of the balloon tip catheter with undiluted positive contrast media. It is necessary to fill the lumen of the urinary catheter to ensure that air bubbles will not be retrograded into the urethra.
Air bubbles can mimic uroliths or other filling defects.
Secure balloon catheter inside urethral orifice and inject an appropriate volume of undiluted contrast media. 3 ml of positive contrast media for cats. 5 to 10 ml for positive contrast media for dogs under 25 lbs. 10 to 15 ml of positive contrast media for dogs from 25 to 50 lb. 15 to 20 ml of positive contrast media for dogs greater than 50 pounds.