Perineal Urethrostomy in Cats

A perineal urethrostomy is a surgical procedure performed on male cats who have had recurrent bouts of urinary obstruction. This occurs when mucus plugs, crystals or stones become lodged in the urethra, which is the thin tube that passes from the bladder to the tip of the penis. Once a blockage develops and the cat is no longer able to urinate, the bladder can rupture and toxins build up in the bloodstream, within 24 hours the cat is in acute kidney failure.


  • Cats who have had repeat urethral blockages which cannot or do not respond to medical management
  • Cats who present with a urethral block that can not be unblocked with a catheter
  • Cats whos urethra has undergone significant trauma or stenosis due to catheterisation

Signs of a urethral blockage

A urethral blockage can be full or partial. In the event of a partial blockage, a small amount of urine may be able to pass, but the urine stream is decreased. The partial blockage can develop into a full blockage, with an incidence of 1.5 to 9% and a median age of 6 years.

  • Reduced stream of urine or absent urination
  • Crying in the litter box
  • Blood in the urine
  • Frequent genital licking
  • Urinating outside the litter tray
  • Painful abdomen
  • Hiding

What does a perineal urethrostomy involve?

If the cat is currently blocked, he will need to be stabilised to correct electrolyte derangements before surgery. Medical care will include fluids as well as emptying the bladder via catheter or cystocentesis, which is a procedure in which the veterinarian inserts a needle through the abdominal wall and into the bladder to remove urine.

A perineal urethrostomy removes the penis and creates a new opening in the wider portion of the urethra, subcutaneous tissue and skin in the perianal region (between the perennial and anus). This wider opening allows plug like substances to pass out of the body, avoiding a blockage.

The cat is placed under general anesthesia as well as a local anesthetic, the area is shaved and the area cleaned. The skin around the penis is cut and dissected to allow the surgeon to access the larger portion of the urethra which is then cut lengthways to open the lining which is then sutured to the surrounding skin to widen the urethral orifice. This allows urine to pass out of the body without contact with the skin which can cause scalding.

Anatomically, the male will look similar to the female post-surgery, and some pet owners and journalists (who should know better) call it a sex-change operation, but there is a difference. When a person transitions from one gender to another, they may elect to undergo gender realignment surgery, including removal of the penis, they identify as female and they receive female hormones and hormone blockers for the rest of their life. The male cat no longer has a penis but does not undergo hormone therapy.


Your cat will be usually be discharged within a day of surgery unless a urinary obstruction had occurred, in which case, he will be discharged in a few days when the veterinarian is confident he is well enough to leave the hospital.

  • The cat will be discharged with an Elizabethan collar to prevent self-trauma until the area has fully healed. Raising pet food and water bowls can make eating and drinking easier during this period.

Bleeding, bruising and swelling may be visible for a week post-surgery. It is important to lift the cat’s tail and monitor the surgical site.

It is important to remember that PU doesn’t address the underlying disease, and stones may continue to develop, but the wider urethra makes it easier for stones to pass out of the cat’s body. Cats with struvite stones can switch to a stone dissolving diet, however, no such diet exists for calcium oxalate stones. Surgery to remove stones from the bladder may be necessary. Increasing water consumption by switching to a canned diet and encouraging the cat to drink with additional water bowls or fountains are also standard therapies.

The veterinarian will schedule a follow-up appointment one to two weeks post-surgery to check on the cat’s progress. Do not remove the Elizabethan collar until your veterinarian has given you the go-ahead.


Cats who have had perineal urethrostomy are at increased risk of urinary tract infections. It is common for the cat to experience some bleeding and urinary incontinence in the first few days after surgery, in most cases this is temporary. If possible, confine the cat to a room with washable flooring during recovery.

  • Strictures are scar tissue that causes a narrowing of the urethra
  • Painful urination (dysuria)
  • Frequent urination (pollakiuria)
  • Blood in the urine (hematuria)
  • Wound separation (dehiscence)
  • Dermatitis
  • Rectal prolapse
  • Perineal hernia
  • Blood clots, which can be large enough to block the flow of urine

Urinary tract infections and strictures are the most common postoperative complications. Revision surgery may be necessary for some cats. Always speak to your veterinarian if you notice any post-operative signs including difficulty urinating, damage or trauma to the surgical site, redness or bleeding and urinary or fecal incontinence.


In a follow-up small study of 86 cats who had a perineal urethrostomy, 10.7% experienced severe signs of recurrent feline lower urinary tract disease, and among the cats who were still alive at the time of the study, most pet owners reported their cat’s quality of life was good.

Frequently asked questions

How much does a perineal urethrostomy cost?

The cost can vary, is the PU needed to unblock a cat in an emergency setting or has it been scheduled? Is the cat’s regular veterinarian performing the surgery or a board-certified veterinary surgeon? Does the cat have any additional underlying diseases which increase his risk of surgery?

The cost of a perineal urethrostomy can start at $900.

How long can a cat live after a perineal urethrostomy?

One long-term study found the median survival time of 86 cats post-PU surgery is 3.5 years.

  • 47 were still alive at the time of the study.
  • Five cats did not survive the first 14 days after surgery.
  • Six cats did not survive beyond 6 months.
  • 27 cats lived longer than 6 months.
  • For 19 cats who were still alive for more than 6 years, 86% categorised their cat’s long-term quality of life as good.

Can a male cat still develop a urethral blockage after perineal urethrostomy?

It is possible if the stone grows large enough but unlikely, especially if therapies are initiated to reduce or prevent stone formation.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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