Perineal Urethrostomy

Perineal urethrostomy (PU) is a surgical procedure used to widen the opening of the urethra in male cats that have experienced repeated obstruction of the urethra and do not respond adequately to conservative therapy with medicine and diet.

To understand how your male cat can get a urinary obstruction, it is important to know some basic anatomy of the urinary tract.The bladder collects urine from the kidneys and contracts to expel its contents during urination via a tube called the urethra. The end of the urethra in a normal male cat is relatively narrow. In affected male cats, mucous plugs, crystals and stones can become lodged in the terminal part of the urethra, preventing the cat from urinating, which results in a potentially fatal buildup of toxins in the cat’s body.

Whenever your cat is showing signs of a health issue your first step is to contact your primary care veterinarian. If it is indicated that your cat may suffer from a urinary tract infection, blocked urethra, or other serious disease, a veterinary specialist is available at an ExpertVet certified hospital.

Signs of Urinary Obstruction

Shortly after urinary obstruction occurs, your pet will go to the litter box and unsuccessfully attempt to urinate. As the bladder becomes more and more distended or stretched out, your pet will display signs of pain, including secluding himself and crying out or growling.

As toxins accumulate in the blood, the cat may experience vomiting, abnormal heartbeats, depression, and in severe cases, coma. These built-up toxins can be fatal to the patient.

Diagnosis of Urinary Obstruction

Finding a very large, firm and painful bladder upon physical examination makes the diagnosis of urinary obstruction most likely. The treating veterinarian will recommend x-rays of the abdomen to rule out a urinary obstruction caused by small stones along the urethra and bladder. Blood will be taken and tested for accumulation of urinary toxins and high potassium levels. Abdominal ultrasound may also be used to evaluate the urinary tract.


Urinary blockage is an emergency; therefore, it is essential to have this condition treated immediately. Your veterinarian will start intravenous fluid therapy, as cats with urethral obstructions are frequently dehydrated.

If your cat’s blood potassium level is very high, glucose (a type of sugar) and insulin may be administered intravenously to lower the level of this electrolyte. The urethral obstruction is relieved by flushing the material out of the urethra and passing a urinary catheter into the bladder. It is most important to rebalance your pet’s blood chemistry and eliminate the built-up toxins. If bladder stones are present, they will need to be surgically removed.

In most patients, the urinary catheter is left in place for at least 24 hours after the obstruction has been relieved, after which, your cat will be carefully monitored for urination. In the event that your cat becomes obstructed again, the process to relieve the obstruction can be repeated. If your pet becomes repeatedly blocked, a perineal urethrostomy may be recommended.

The perineal urethrostomy essentially removes the narrow section of the urethra, which is located within the penis. During the procedure, the penis is removed and the urethra is opened at the level of the pelvis where it becomes wider and more distensible. The edges of the urethra are then sutured to the edges of the skin of the perineum using very fine sutures to create a new opening

If the cat has not been neutered, this procedure will be performed during the surgery