What to do when urethral catheterization is not possible (Proceedings)

1. Patient Presentation

a. Male cat presented for "constipation" for a day
b. Abdominal palpation reveals a very large, painful, and hard urinary bladder.
c. You tell the owner: "No problem."
d. Famous last words!

2. Your Attempts

a. Anesthesia is given.
b. A catheter is chosen and lubricated.
c. In spite of repeated efforts, pleas for Divine intervention, and promises to God, you cannot get the catheter to pass into the bladder.

3. What to do Next

a. Radiograph the abdomen caudal enough to include the urethra.
      i. You should do this with all obstructed cats.
b. Empty the bladder with a cystocentesis.
c. Attempt catheterization again
      i. Immediately.
      ii. If that is not successful, in 6-12 hours.

4. Possibilities

a. Urolith in the urethra, most commonly composed of calcium oxalate. *****
b. Soft tissue stricture ***
      i. In urethra.
      ii. In penis.
      iii. Usually due to prior difficult or abusive catheterization.
c. Heavy struvite crystalline debris in the bladder and urethra. *
d. Urethral tumor. *

5. Two Important Diagnostics

a. Plain Radiographs of Abdomen
      i. Take a lateral view caudally enough to include the urethra.
      ii. A struvite urolith is less radiodense than a calcium oxalate urolith and could be missed with a film radiograph. Consider digital (DR) radiography for your practice.
b. Urethrogram
      i. Technique
           1. Anesthesia.
           2. Pass a catheter about 0.5-1.0 cm into the urethra.
           3. Occlude the urethra around the catheter.
           4. Inject 1 ml of an IV-approved contrast material (MD-76R or Omnipaque); do not use barium.
           5. Take a lateral radiograph immediately with the catheter still in the urethra.
           6. A normal urethra has a slight bulge at the level of the bulbourethral glands. This is seen about the level of the caudal end of the pelvis.
           7. Note: If the stricture is in the penis so a catheter cannot be passed, you will not be able to perform a urethrogram; go to surgery immediately.