A urinary tract infection is never comfortable, but for a cat who cannot urinate, the pain associated with an inflamed urinary tract may be the least of their problems. A urethral obstruction, or urinary blockage, can be life-threatening for cats, so cat owners must know the signs.

What is feline lower urinary tract disease?

Feline lower urinary tract disease (FLUTD) is not one specific disease—the term FLUTD is used to describe the many conditions that can affect a cat’s urinary bladder and urethra. To complicate the issue, each disorder shows similar signs, making accurate diagnosis of urinary issues complicated, and determining the causes extremely difficult. 

For example, young, otherwise healthy cats most frequently develop a condition called feline idiopathic cystitis (FIC), which has no discernable cause. FIC cats present with signs that are similar to a urinary tract infection (UTI), but have no bacteria in their urine. Therefore, an FIC diagnosis has to be a diagnosis of exclusion, meaning similar conditions must be ruled out to achieve this diagnosis. 

What causes urethral blockage in cats?

A urethral blockage is a serious, potentially life-threatening urinary condition that affects cats—usually male cats, because their narrow urethra is more likely to become blocked than a female cat’s. Several conditions can lead to a urethral obstruction, including:

  • A urethral plug — Proteins, cells, crystals, and debris from the bladder can form a mucus plug that lodges in the urethra.
  • A urolith — A urolith (i.e., a urinary stone, or a collection of tiny stones) that forms in the bladder can block urine flow out of the urethra.
  • Urethral swelling and spasms — When the bladder and urethra become inflamed because of stress, infection, or any other cause, the inflammation can lead to swollen urethral walls that create a blockage. Occasionally, inflammation and irritation cause the urethral sphincter muscle to spasm, which can also obstruct the urine if the cat cannot relax the muscle.

Obesity, stress, poor litter box hygiene, and inadequate hydration all contribute to urinary issues in cats, so ensuring you provide environmental enrichment, exercise opportunities, water fountains, and clean litter boxes is vital for alleviating their urinary problems.

What are urethral blockage signs in cats?

Many feline urinary conditions, including an early stage urethral blockage, look similar, which means you must take prompt action at the first sign of an abnormality to resolve a blockage before the problem becomes life-threatening. Signs of urinary problems in cats include:

  • Frequent urination, typically in small amounts
  • Increased thirst
  • Decreased appetite
  • Frequent trips to the litter box
  • Straining to urinate
  • Blood in the urine
  • Inappropriate elimination outside the litter box
  • Vocalizing when urinating (e.g., meowing, yowling)
  • Reclusive behavior

If a urinary issue progresses to a urethral blockage, your cat will likely repeatedly attempt unsuccessfully to urinate, cry in pain when trying to urinate, and may become agitated and vomit. A cat’s urethral obstruction is a life-threatening emergency, and can quickly become fatal if left untreated.

How is urethral blockage in cats diagnosed?

Diagnosing a urethral blockage in a cat is relatively simple. Their clinical signs, including a large, firm bladder that can easily be palpated but is painful when touched, paired with a history of urinary issues, can lead to a quick diagnosis and prompt treatment. Blood work is essential for determining the level of kidney damage, since a urethral obstruction can cause kidney issues  that have a poor prognosis. 

How is urethral blockage in cats treated?

Once a cat’s urethral blockage is diagnosed, they need their electrolyte levels restored to normal and their bladder quickly emptied. Generally, our veterinary team will pass a urinary catheter up the urethra, flush out any debris, and suture an indwelling urinary catheter in place to help prevent reblocking over the next two to three days. Pain, anti-inflammatory, and antispasmodic medications may be necessary over the next several days, along with intravenous fluids, as the patient returns to normal.

To prevent a blockage from recurring, we may recommend a prescription urinary diet to minimize urolith formation. Managing your cat’s household and environmental stress, encouraging them to drink plenty of water, and providing enough clean litter boxes for all the cats in your home will help prevent FIC flare-ups, which can contribute to a urethral obstruction.

Urinary issues in cats can quickly become serious problems, so don’t hesitate to contact your Wales Animal Clinic team for an appointment if your cat is straining to urinate, or you see blood in their urine.