Urinary Blockage In Cats: What All Cat Owners Should Know

A urinary blockage in cats is a very common and serious condition that can become fatal quickly if the symptoms are not noticed. The condition is caused by a blockage in the urethra, which is the tube that carries urine from the bladder to the outside of the body. When the urethra is blocked, urine cannot flow properly and can back up into the bladder leading to the buildup of uremic toxins into the bloodstream. This is a very serious condition and can become fatal quickly if the symptoms are not noticed. The goal of this blog article is to educate cat owners as to the symptoms and disease of urethral obstruction in cats.

What is a urinary blockage in cats and what are the symptoms?

A urinary blockage in cats is due to the obstruction of urine flow through the urethra. Urethral obstructions have been diagnosed in 1.5% of all cats that were seen at veterinary teaching hospitals over a 19-year span.

Urethral obstruction in cats can be due to either physical or mechanical causes. Examples of physical blockages include stones or inflammatory plugs. With mechanical urinary blockage in cats, there is a urethral spasm or edema (swelling) present.

The most common symptoms of urinary blockage in cats are urination outside of the litter box, straining to urinate, blood in the urine, and vocalizing in pain. If you notice any of these symptoms in your cat, it is important to take him or her to the veterinarian as soon as possible. Symptoms are often a consequence of the buildup of uremic toxins in the bloodstream. For reference, the most common symptoms of urinary blockage in cats include:

• Vocalization in the litter box
• Repeated attempts to pass urine and straining
• Vomiting
• Anorexia (decreased appetite)
• Lethargy and hiding
• Weakness and mental dullness

What are the causes of urinary blockage in cats?

There can be many different causes of urinary blockage in cats, but the most common are urinary crystals, stones, and inflammatory plugs.

A study of cats with urinary blockages found that 60% had urethral inflammatory plugs, 20% had stones, and <5% had urethral strictures or cancer. The remainder of the cases were idiopathic with no underlying cause. The most common cause of urethral plugs that can lead to urinary blockage in cats is feline idiopathic cystitis.

Inflammatory urethral plugs

Urethral inflammatory plugs typically form with idiopathic cystitis, urinary tract infections, or as a reaction to urinary crystals or stones. Urethral plugs are made up of mucus, inflammatory cells, and debris. The plug can be found anywhere along the length of the urethra but is most commonly seen in the distal urethral at the tip of the penis. In some cases, crystalline material can be visualized on the prepuce of male cats.

Urinary crystals

Urinary crystals form when minerals in the urine crystallize and become solid. The most common type of urinary crystal is struvite, but there are other types as well. Urinary stones are made up of different minerals and can vary in size. Some stones can be as small as a grain of sand, while others can grow to be the size of a pea. Inflammatory plugs are made up of cells and proteins that accumulate in the urethra and can obstruct urine flow.

Bladder stones

Stones that cause urinary blockage in cats are usually composed of struvite or calcium oxalate. These stones can form when the urine pH becomes too alkaline (high) or too acidic (low) respectively. The most common risk factor for urinary blockage in cats is the presence of urinary crystals.

How is a urinary blockage in cats treated?

The goal of treatment for urinary blockage in cats is to resolve the obstruction and prevent a recurrence. Treatment will also focus on supporting the cat while the obstruction is resolved and addressing any underlying causes.

As a urinary blockage in cats is a medical emergency, your veterinarian will work quickly to relieve the obstruction. This may involve passing a urinary catheter to bypass the obstruction or flushing the urethra with sterile saline. If there is an associated urinary tract infection, antibiotics will be prescribed. After the urinary blockage has been addressed, your cat will likely spend a few days in the hospital for monitoring and intravenous fluids to flush out the uremic toxins. Veterinarians also want to make sure the cat can urinate on its own in the animal hospital prior to discharge.

Your veterinarian will likely also prescribe a muscle relaxant such as prazosin to help reduce spasms within the urethral and allow for improved voiding of urine.

Once the obstruction is relieved, your veterinarian will work to identify and treat the underlying cause. This may include dietary changes, medications, or surgery. Dietary changes can help to prevent urinary crystals and stones from forming. Medications can be used to treat urinary tract infections or to dissolve urinary crystals. Surgery may be necessary to remove stones or to repair a urethral blockage.

A surgical procedure called perineal urethrostomy is often performed in male cats with recurrent urinary blockages. This procedure involves making an incision in the perineum (the area between the anus and scrotum) and creating a new opening for the urethra. This procedure is usually reserved for male cats with repeated urethral blockages.

What are the potential complications of a urinary blockage in cats?

Complications are uncommon but can occur in cats. Among the potential complications are kidney failure; cardiac arrhythmias due to hyperkalemia (increased blood potassium); urethral lacerations or tears; urinary tract infections secondary to catheterization; urine in the abdomen (uroabdomen); persistent lower urinary tract disease; and bladder rupture.

What is the prognosis for cats with urinary blockage?

The prognosis for cats with urinary blockage is generally good if the obstruction is treated promptly. However, urinary blockages can recur and some underlying causes may not be able to be completely resolved. Your veterinarian will work with you to develop a treatment plan that is best for your cat.

Overall, the good news is that studies have shown a favorable prognosis for most cats. Using traditional treatment protocols, the survival rate to discharge is reported as high as 95%.

What are some tips for preventing urinary blockages in cats?

To prevent the recurrence of urinary blockages in cats, precautions must be taken at home. If your cat has struvite stones, your veterinarian may prescribe a urinary diet to help reduce crystalluria and dissolve the stones. Increased water consumption is very important in reducing the risk of further urinary blockage in cats. We recommend that high-risk male cats be fed at least 50% of their daily caloric intake in the form of canned food. This will increase water consumption and ideally create a slightly dilute urine, therefore reducing the risk of urethral obstruction.

Frequently asked questions about urinary blockage in cats from cat owners

Urinary blockage in cats is a medical emergency. This condition can easily become fatal if the symptoms are not noticed. The causes of urinary blockage in cats can be due to urinary crystals, stones, or inflammatory plugs. With proper treatment, the prognosis can be good and prevention depends on the cause of the urinary blockage. The best prevention is to feed your cat a high-quality diet with at least 50% of the daily amounts in the form of canned food. If you have any further questions about urinary blockage in cats, please contact your veterinarian.