Perineal Urethrostomy (PU) in Cats
Dr. Cathy Reese
History. Your veterinarian will ask you many questions regarding the development and progression of the problem. If your pet is obstructed and unable to urinate, he may require emergency stabilization. This could include intravenous fluids, and emergency urethral catheterization or other method of relieving the pet of urine.
Physical exam. Your veterinarian will perform a complete physical exam. This includes listening to the heart and lungs, taking the pet's temperature, and palpating the abdomen. Your veterinarian will assess your cat's bladder for size, pain and the ability to express urine.
Radiographs (x-rays). Radiographs are often taken to look for stones in the bladder, urethra or other parts of the urinary tract. They are also necessary if the animal was involved in a traumatic event to look for injuries to the ribs, diaphragm and lungs.
Ultrasound. An ultrasound (sonogram) of the abdomen is often helpful to identify stones in the urinary tract and to evaluate the other organs in the abdomen.
Blood and urine tests. Blood and urine tests are submitted to look for anemia, evaluate kidney and liver function prior to anesthesia, and evaluate the oxygen and electrolyte levels in the blood. All of these tests are important in determining if the pet is stable for anesthesia. Animals that are unable to urinate can have severe abnormalities in their kidney values and electrolyte levels, requiring intravenous (IV) fluid therapy as well as monitoring the heart for abnormal rhythms.
Emergency stabilization: If your pet is unable to urinate, and has severe abnormalities in his blood work, emergency stabilization may be necessary. This involves IV fluids, heart monitoring and passing a urinary catheter to relieve the obstruction.
If the obstruction cannot be relieved via urethral catheterization and the cat is not stable for a prolonged anesthesia and surgery, emergency methods of draining the bladder and/or eliminating the blood waste products are necessary. An emergency cystostomy can be done, which involves placing a tube directly into the bladder to drain the urine. Alternatively, a peritoneal dialysis catheter can be placed, which is a catheter placed in the abdominal cavity. Fluid is infused into the catheter to dilute and remove the blood waste products that have accumulated as a result of the urethral obstruction.
Once the pet is stable and a perineal urethrostomy has been determined to be necessary, or if the obstruction cannot be relieved, your pet is placed under general anesthesia and surgery is done.
The surgery involves removing the penis and scrotum (and testicles if the cat has not already been castrated) and making a new opening in the wider area of the pelvic urethra. The urethral lining (mucosa) is sutured to the skin of the perineum. The skin will heal to the mucosa, creating a new permanent urethral opening.
After surgery, an Elizabethan collar is placed on the cat to prevent him from licking the new urethral opening. The abrasive tongue can damage the healing tissues. Your pet will need to be monitored and treated for pain and any other abnormalities found in the blood work. This can involve IV fluids and may require a few days in the hospital.
If stones were removed, they are submitted for analysis to see what type of minerals they are made of. A diet change may be necessary to prevent their recurrence.
Antibiotics may be necessary, especially if there was a concurrent urinary tract infection.
After about two weeks, your cat must have the stitches removed from the urethrostomy site. They may be removed after the cat has been sedated. Removing stitches in this sensitive area is mildly uncomfortable and if the cat moves suddenly during suture removal, the new urethral opening can be damaged.
If the urethrostomy does not heal appropriately or becomes damaged, it can scar or completely close down. This is called a "stricture" and requires further surgery to re-open the urethra.
Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve.
Administer all prescribed medications as directed. Alert your veterinarian if you are experiencing problems treating your pet.
Closely follow your veterinarian's instructions for post-operative care, including exercise restriction for 1-2 weeks. This allows the incision to heal.
Contact your veterinarian right away if your pet has difficulty urinating.