We’ve talked before about urinary conditions in cats and dogs, including the frustrating condition known as FLUTD (feline lower urinary tract disease) in cats and bladder stones in dogs. While these conditions often confound us and result in numerous rechecks, occasionally they can end up being life-threatening for our pets. That’s because FLUTD sometimes leads to urethral plugs that block the urethra. Bladder stones can also become lodged in the urethra and prevent the passage of urine.

What causes a urinary obstruction?

Urinary obstructions are common conditions that we see in both cats and dogs, but male cats are particularly prone due to their narrow urethra. When the conditions are favorable in the feline bladder, a buildup of mucus and urinary crystals can form into a matrix that plugs the urethra, preventing the cat from voiding urine.

In the same way, bladder stones can occasionally travel from the bladder to the urethra in our pets. If the stones are larger than the urethra, they will be unable to pass, causing a urinary obstruction.

Urinary obstructions are ALWAYS an emergency. If your pet is showing signs of a urinary obstruction, prompt medical care is important, as the condition can be fatal.

Signs and symptoms 

Pets with urinary tract infections or FLUTD have symptoms that may mimic a urinary obstruction. The bladder and urethral inflammation they are experiencing results in an urge to urinate, even if they have already voided all of their urine. Frequent, small urination is the hallmark of urinary tract disease, and often the urine is bloody.

When pets have urinary obstructions, they may also ask for frequent walks to urinate or make frequent trips to the litter box. However, in cases of urinary obstruction, your pet will be unable to urinate. Though they have a full bladder, urine is unable to exit through the urethra due to the obstruction. Straining to urinate without producing urine is an important symptom to pay attention to, and one that should result in a veterinary visit as soon as possible. Do not delay.

The kidneys filter toxins from the blood and allows them to be discarded by the body through the urine. When a urinary obstruction is present, toxins build up and severe metabolic disturbances occur. Potassium build-up can result in fatal heart arrhythmias, and the kidneys are under strain as urine backs up. Urinary obstructions can cause death within three days if untreated.

It's simple.We have the most comprehensive pet insurance for cats & dogs.


The first thing your veterinarian will want to do if your pet has a urinary obstruction is to relieve the actual obstruction to allow urine to flow. In almost all cases, sedation is required so that a urinary catheter can be placed. If the passage of a urinary catheter is not possible, emergency surgery will be required to remove the blockage. Urinary obstructions in cats can almost always be resolved non-surgically, but this is not always the case in our canine friends. If bladder stones were the cause of the blockage, your veterinarian may wish to surgically remove addition stones if they are present in the bladder to prevent another obstruction in the future.

After the obstruction is relieved, your pet will likely need several days of hospitalization for supportive care while he or she recovers. Intravenous fluids and correction of electrolyte imbalances, as well as pain medications and medications to prevent urethral spasms, will be administered. After the urinary catheter is finally removed, your pet will likely stay several hours to make sure that he or she can urinate before being released from the hospital.

Risk of recurrence

Male cats who have experienced a urinary obstruction are at an increased risk of recurrence. Owners are instructed to encourage their cat to drink plenty of water by switching to an exclusively canned diet and the placement of recirculating water fountains around the house. A prescription diet may be started to make the conditions in the bladder less favorable for the formation of the crystalline matrix that causes urethral plugs.

Despite our best efforts, sometimes male cats continue to experience repeated urinary obstructions. When this occurs, a corrective surgery called perineal urethrostomy may be in order.

Again, urinary obstructions can be fatal and should always be considered a veterinary emergency. If you suspect this condition is present, call your veterinarian right away. If it is after hours, this is one of those emergencies that can’t wait until morning, so call your local emergency clinic and head on over. Prompt care ensures a more positive result!

Sep 5, 2013
Pet Health

Get covered with Petplan

An insurer who cares about your pets (nearly!) as much as you do.

Start quote

More from 

Pet Health


View All

Join Our Newsletter and Get the Latest
Posts to Your Inbox

By subscribing you agree to our terms and conditions.
No spam ever. Read our Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.