Urinary Obstruction

Urinary blockage is one of the most common feline emergencies that results when the urethra is blocked, resulting the the cat being unable to pass urine from the urinary bladder.  Th nature of the blockage can be clusters of bladder crystals, bladder stones, or mucus plugs.  Signs of feline lower urinary tract disease include straining to urinate, bloody in the urine, unusually frequent urination, etc. Male cats are at highest risk for development of urinary blockage.

Mucus, crystals and tiny bladder stones can clump together to form an obstructive plug in the narrow and twisting male cat urethra. The passage is so narrow that it does not take much to obstruct urine flow. As cats strain to urinate, they will produce small amounts of urine or no urine at all.

It can be challenging to know if a cat is just straining because he is experiencing inflammation, versus experiencing a progressive obstruction.   This is potentially the mother of all feline emergencies, so if in doubt, get him to a veterinarian ASAP.

On the initial assessment, the veterinarian will palpate the bladder by gently pressing on the abdomen.  If there bladder is largely distended with urine, the veterinarians will gently apply pressure to see if the obstruction can be blown out with a little assistance.  If the bladder will not express, then the kitty is sedated for a urinary catheter to be passed and the obstruction relieved.  Sedation protocols will vary between veterinarians.

Once the catheter is placed, it is generally sutured in place with a urine collection bag.  Pain and inflammation medications, as well as antibiotics are commonly administered and the cat will be hospitalized for 24-48 hours.

Blood work is generally run to rule out or rule in compromise of the kidneys that can be experienced following an active obstruction.  If the kidneys are compromised, the patient is generally treated with aggressive IV fluids. The fluids also serve to flush out the urinary bladder.

A urinalysis is typically run to determine the root cause of the obstruction. In most cases of crystals production caused from abnormalities in urine pH, obstruction can be prevented by exclusive feeding of urine pH stabilizing prescription diets,

A disease unique to cats, called idiopathic cystitis, is a common cause of obstruction.  This disease results from inflammation of the bladder that does not appear to have an underlying cause.  It is largely believed that stress plays some roll in idiopathic cystitis, so stress management is commonly recommended using pheromone therapy and making changes in the home gradual to minimize stress.  An example of pheromone therapy available at most pet stores and online is called Feliway.  It is not always preventable, so surgery may be necessary to prevent future obstructions.

If a cat blocks a second time, many veterinarians commonly consider recommending a surgical procedure that straightens and widens the feline urethra called a Perineal Urethrostomy.  It is performed by removing the thinner, twisty portion of the feline urethra and suturing the wider, straighter portion of the urethra closer to the neck of the bladder directly to the skin.  In the hands of an experienced and skilled surgeon, the surgery is 90% percent successful.

Roger L. Welton, DVM

Founder and Chief Editor, Web-DVM.net

CEO Premier Veterinary Care

Host Space Coast Pet Podcast

Author, The Man in the White Coat

Article updated 3/10/2026