Perineal Urethrostomy

June 29, 2024

 Nancy Kerr

 

As some of us know, male cats can develop a complete or partial inability to pass urine through the urethra (the tubular structure connecting the urinary bladder to the penis) due to an impediment. Signs of this can include straining to urinate, frequent attempts to urinate including outside the litterbox, blood in the urine, licking at the penis, etc.

A trip to an emergency veterinarian usually resolves the issue. However, if there is an obstruction that cannot be removed or if there is traumatic injury to the penis, the vet may recommend doing a perineal urethrostomy (PU). “This is a surgical procedure that is most commonly performed on male cats with a urinary obstruction,”¹ where it is indicated that the blockage cannot be relieved or re-blockage is highly likely.

What Is a Perineal Urethrostomy?

The first time that you hear the term may be after several trips to the emergency vet to have your cat unblocked, and/or the unfortunate situation of damage to the cat’s penis.  There are cases where a cat has been in so much pain due to being unable to pee that he has damaged his penis by constantly licking at it. A perineal urethrostomy is a procedure that “removes the narrowest part of the urethra (the tube that transports the urine from the bladder to the exterior of the body), allowing easier urination along with a lower risk of re-obstruction.”¹ This surgery can decrease the chances of an obstruction reoccurring and, in the case of a damaged penis which may require catheterization, may also allow the cat to pee without a catheter.

Male vs. Female

Male cats are more likely to develop this issue than female cats due to the differences in the urinary tract anatomy between the two. “While the female urethra is relatively short and maintains a consistent diameter as it travels from the bladder to its external opening, the male urethra is slightly longer and, more importantly, it narrows as it enters the penis.”¹ This makes the male more susceptible to obstructions that may cause the urethra to become blocked by “stones, blood clots, mucus or tumors.”¹

When Is Perineal Urethrostomy Done?

The surgery is commonly done if a urethral obstruction within the penis cannot be relieved with a urinary catheter. This will allow the cat to pee on his own by re-establishing the urine flow. It may also be done in the case of frequent urinary obstructions. Male cats “may benefit from a perineal urethrostomy to decrease the likelihood of future obstructions”¹ by providing a bigger hole for the flow of urine. Scarring from previous blockages (which can constrict tissue) is a predisposing factor in many cases, although in very rare cases a perineal urethrostomy could be recommended with the first episode.

Cost

The cost for the surgery can vary depending on the tests needed and the extent of the condition. It could range from around $2200 to $4400 USD. Multiple trips to the emergency vet, especially to remove a blockage to enable the cat to urinate, could quickly cost more than the surgery. Check with your pet insurance provider to see if the surgery is covered or if it is considered a complication due to a pre-existing condition.

Procedure

The procedure for the surgery involves removing the penis, then “suturing the deeper, larger-diameter region of the urethra to the skin to create a new urinary opening.”¹ What happens if the procedure is being performed on a breeding male? If the cat is still intact, castration is necessary to do a PU, and the cat will no longer be able to be breed. Afterwards, the cat will need to wear a temporary collar to prevent access to the surgery site to prevent infection. It should be noted that some cats are really good at getting out of the plastic Elizabethan-type collars. While healing, the cat will also need to be kept calm, have restricted activity, and be in a separate area from other cats. The vet may also recommend a special urinary diet and/or drugs to keep the cat calm and complication-free as possible.

Complications

Complications from the surgery may include an atonic bladder, one that is flaccid “due to chronic overstretching of the bladder muscle, which can no longer contract and expel urine.”² This should resolve after seven days of treatment with urinary catherization and medication. Bleeding from the surgical site should abate if the cat is not able to lick it. Bladder infection is the most common complication. Since some cats do not show any signs of this, “urine culture rechecks should be done every six to 12 months due to an increased risk for ascending urinary tract infections.”³

Other complications include “subcutaneous urine leakage in the perineal region, hemorrhage, urinary tract infection and incontinence. Although some of these complications can be managed conservatively, many require surgical revision to restore urinary function.”³

The most devastating complication that occurs within the first six weeks after surgery is a narrowing of the urethra due to scar tissue, which can lead to problems emptying the bladder. The warning signs are the same as those for urinary obstruction, but “additional surgery attempting to fix this usually has [only] a 50% success rate.”²

Prognosis

Most of the cats who undergo this procedure go on to have healthy and normal lives. However, a “perineal urethrostomy does not prevent bladder inflammation or stone formation so the clinical signs of urinary tract disease may continue in some cats.”⁵

Cats that have underdone PU surgery can still be shown in CFA. According to the 2024-2025 show rule 6.12, section f, cats who have had this procedure can be shown in Premiership.

1. 6.12 A cat or kitten not having all its physical properties – eyes, ears, legs, tail, claws, both descended testicles (adult cat only) – or has had surgery which changes a cat’s natural functions (e.g. tendonectomy), is not eligible for entry. The previous notwithstanding, cats missing certain physical properties, as listed below, are eligible for entry in the category (class) indicated:

1. 1. Altered cats in the Premiership classes;
   2. Altered cats and kittens in the Household Pet classes;
   3. Altered kittens in the Kitten classes;
   4. Kittens without descended testicles in Kitten classes;
   5. Recognized naturally tailless or naturally partially tailless breeds in Kitten, Championship or Premiership classes;
   6. Cats having had a perineal urethrostomy operation in the Premiership Classes.⁶

 

So, when urethral blockage threatens a cat’s life, although a PU can end a stud male’s ability to breed, it can also add to the cat’s comfort and longevity.

Source Notes

1. Perineal Urethrostomy Surgery in Cats, Malcolm Weir, DVM, MSc, MPH; Catherine Barnette, DVM, accessed April 21, 2024, https://vcacanada.com/, https://vcacanada.com/know-your-pet/perineal-urethrostomy-surgery-in-cats
2. Feline Perineal Urethrostomy, 10/2/2011, accessed April 21, 2024, https://www.animalsurgicalcenter.com/, https://www.animalsurgicalcenter.com/feline-perineal-urethrostomy
3. Christopher Adin, DVM, DACVS, How to perform a feline perineal urethrostomy, 11/11/2015, accessed April 21, 2024, https://www.dvm360.com/, https://www.dvm360.com/view/how-perform-feline-perineal-urethrostomy
4. Clara S.S. Goh, BVSc, MS, Diplomate ACVS, and Howard B. Seim III, DVM, Diplomate ACVS, Feline Perineal Urethrostomy Ventral Approach, 07-08/2014,

accessed April 21, 2024, https://todaysveterinarypractice.com/, https://todaysveterinarypractice.com/urology-renal-medicine/practical-techniques-from-the-navc-institute-feline-perineal-urethrostomy-ventral-approach/

5. Urinary Obstruction in Male Cats, accessed April 21, 2024, https://www.acvs.org/, https://www.acvs.org/small-animal/urinary-obstruction-in-male-cats/
6. The Cat Fanciers’ Association, Inc, Show Rules (2024-2025), Page 9, 6.12f, accessed April 22, 2024