• Feline urethral obstruction is a potentially fatal condition, usually seen in male cats, during which urine is prevented from leaving the bladder.
  • The urethra may be plugged with mucus, urinary sediment, or small bladder stones.
  • Diet and bladder infections can have a role in the formation of urinary stones and sediment.
  • Treatment involves relieving the blockage and treating complications caused by the obstruction.
  • Feeding a special diet, increasing water intake, and treating urinary tract infections early can reduce the risk of future urethral obstructions.

What Is Feline Urethral Obstruction?

Urine flows from the kidneys down the ureters and into the bladder, where it is stored until it is released through the urethra. A urethral obstruction occurs when the urethra becomes blocked, preventing urination. There are many possible reasons for a blockage, including urinary stones, mucus or sediment plugs, blood clots, tumors, and scarring.  Although any animal is susceptible to a urethral obstruction, male cats are at greater risk for urethral blockage than dogs or female cats because their urethras are narrow and long, making them easier to plug.

A urethral obstruction is usually caused by a buildup of solid material in the bladder that is unable to fit through the urinary opening.  Urinary sediment (crystals), mucus, and inflammatory cells can accumulate in the urine and form a urethral plug. In addition, bladder stones (alone or in combination with other material) may get caught in the urethra on their way out of the body.

Urethral obstruction can cause life-threatening complications. If urine is prevented from exiting the bladder, pressure within the urinary tract can damage the kidneys. Urine contains metabolic waste products that the body needs to eliminate; urethral obstruction causes these toxins to build up.  Another possible complication of urinary obstruction is scarring of the urethra, which makes it even narrower and prone to future blockages. In addition, the bladder wall may be stretched to the point where muscle function is lost; in the worst cases, it ruptures.

A urethral obstruction is an emergency situation, and you should go to your veterinarian immediately if you suspect that your pet is “blocked.” If not treated quickly, pets with a urinary obstruction can die from complications.

What Are Signs of Feline Urethral Obstruction?

If your male cat tries multiple times to urinate and produces just a few drops of urine or none at all, chances are good that he is completely or partially blocked. As the condition progresses, he may show evidence of abdominal pain and yowl when touched or when trying to urinate. Within 24 hours, he may become lethargic, not wanting to get up, move, or eat. If left untreated, a urinary obstruction can be fatal. It is very important to get your pet to the veterinarian as soon as you suspect a urinary obstruction.

How Is Feline Urethral Obstruction Diagnosed and Treated?

As soon as you arrive at your veterinarian’s office, your pet will be examined to determine if his bladder is enlarged and whether an obstruction is likely. If an obstruction is confirmed, hospitalization for emergency treatment and stabilization will likely be recommended. Diagnostic testing, procedures, and treatments will be aimed at evaluating the pet, relieving the obstruction, and addressing the complications associated with the obstruction. Your veterinarian may recommend any or all of the following:


  • Blood work to assess toxin levels and hydration status
  • Urinalysis to look for an infection and/or crystals
  • Urine culture to determine if there is an infection and, if so, what bacteria may be responsible
  • Radiographs (x-rays) to look for bladder or urethral stones


  • Intravenous catheter placement, which allows for fluids and medications to be administered
  • Removal of urine directly from the bladder, which allows for easier urinary catheter insertion
  • Urinary catheter placement (under heavy sedation or general anesthesia), which provides a way to flush the bladder and keep it empty for 1 to 3 days while inflammation subsides


  • Intravenous fluids, which maintain blood pressure, correct dehydration, and help the body rid itself of toxins
  • Antibiotics, which treat bacterial infections
  • Antispasmodics, which relax the urethra in order to allow material to pass through it
  • Cystotomy (surgery to remove bladder stones)
  • Perineal urethrostomy, which is surgery to make the urethral opening permanently larger, thus reducing the risk of future obstructions
  • Long-term dietary changes and urine monitoring

How Can I Prevent Feline Urethral Obstruction?

Unfortunately it is very difficult to prevent feline urethral obstructions, as it is not always known what causes them in the first place. Bladder infections may have a role in the formation of urinary sediment and stones, so infections should be treated promptly. Increasing water intake may also be beneficial. Several diets can help reduce the risk of urethral obstruction in cats that are prone to this problem. Ask your veterinarian if your cat should be on a special diet to reduce the risk of urethral obstruction.