Urethrostomy and Urethrotomy


Urethrostomy: is a permanent procedure to bypass the penile urethra, when a disease such as a stricture, stone or tumor is preventing urination. This is most commonly performed in cats, although it can be performed in dogs.

Urethrotomy: is a temporary procedure to bypass the penile urethra when a disease such as stricture, stone or tumor is preventing urination. This procedure is performed in dogs. In dogs, it is the creation of an opening at the base of the os penis near the scrotum which allows the dog to urinate and pass small stones. The opening is allowed to close up and heal on its own. There is A LOT of bleeding due to the large vascular supply, pressure of urine flow and contraction of urethral smooth muscle every time the dog urinates for up to 2 weeks.

Urethral Obstruction and Perineal Urethrostomy in Cats:

Male cats often develop obstruction of the urethra because the urethral diameter is very small. The obstructions are often the result of mucous plugs, inflammation, small crystals or stones. Unfortunately, research has yet to determine the cause of the inflammation and stone formation, though some believe viral and/or bacterial infections, stress, genetics as well as diet may play a role.

Signs or Symptoms:

Most affected cats are young to middle age.

  • Straining to urinate
  • Frequent urination
  • Blood in the urine
  • Painful urination
  • Inappropriate urination (urinating somewhere other than the litter box).
  • Attempt to urinate in the litter box or elsewhere but will not produce urine.
  • Constipation
  • Crying
  • Hiding
  • Restless
  • Loss of appetite
  • Lethargy
  • Vomiting
  • Death

Fortunately, most cats are successfully unblocked. However, cats who have experienced multiple episodes of urethral obstruction and in rare cases when the obstruction cannot be relieved, a surgical procedure called a perineal urethostomy should be performed. This surgery, removes a portion of the penis creating a wider opening of the urethra. Following a perineal urethrostomy, the likelihood of future obstructions will be decreased. This procedure will not reduce crystal, stone or mucous plug formation.

Surgical Risks:

  • Bleeding
  • Swelling at the surgery site
  • Stricture (scarring and narrowing) of the urethrostomy site
  • Urine leakage under the skin resulting in bruising and infection

The prophylactic benefits of minimizing recurrent urethral obstruction by urethrostomy must be weighed against against surgical risks. Perineal urethrostomy should be limited to pets with a history of multiple obstructions and those in which successful relief of obstruction via passage of a urethral catheter is unsuccessful.