Complete Guide to Feline Lower Urinary Tract Disease: Symptoms, Treatment & Prevention

What is FLUTD?

“Feline Lower Urinary Tract Disease” (FLUTD) is an umbrella term for conditions affecting the bladder and urethra. It’s not a diagnosis itself, but rather describes a collection of symptoms.

Research shows the main causes of FLUTD are:

Why Male Cats Are at Higher Risk

Male cats have a longer and narrower urethra than females, especially within the penis where the diameter is only about 1 millimeter. This means crystals, stones, or mucus plugs can easily cause complete obstruction at this point.

When the urethra is completely blocked, urine cannot be expelled, and toxins build up in the body, leading to:

• Acute kidney failure
• Hyperkalemia (dangerously high potassium, which can cause cardiac arrest)
• Bladder rupture

This is a true emergency. Untreated urethral obstruction can be fatal within 24-48 hours.

Recognizing the Symptoms

Common Signs

• Frequent trips to the litter box with little or no urine output
• Crying or vocalizing during urination
• Blood in urine (pink or red)
• Urinating outside the litter box
• Excessive licking of the genital area
• Prolonged squatting in urination posture

Main Causes Explained

1. Feline Idiopathic Cystitis (FIC)

FIC is the most common cause of FLUTD, accounting for over half of all cases. “Idiopathic” means no specific cause (like infection or stones) can be identified after testing.

The 2025 international guidelines describe FIC as a “threat-responsive disorder”—when cats perceive environmental stress, abnormal interactions between the nervous system and bladder trigger inflammatory symptoms.

Common Triggers:

• Environmental changes (moving, renovations, new furniture)
• Household changes (new pets, new baby, someone moving out)
• Litter box issues (too few, poor location, not clean enough)
• Resource competition in multi-cat households
• Changes in owner’s schedule

2. Urinary Stones and Crystals

Urinary stones (uroliths) form when minerals in urine crystallize and aggregate into solid masses. Before forming complete stones, they may exist as “crystals” or “sandy” sediment.

The two most common stone types in cats have very different characteristics:

Struvite stones in cats are almost always sterile (unlike dogs, where struvite is often infection-related). The good news is that struvite can be dissolved with special diets.

Calcium oxalate stones cannot be dissolved with diet and must be removed surgically or through other methods. Causes may include hypercalcemia, high dietary oxalate, or metabolic abnormalities.

3. Urethral Plugs

Urethral plugs are soft material made of protein, cellular debris, crystals, and mucus that block the urethra. Unlike stones (which are hard), plugs are soft. They occur almost exclusively in male cats.

Diagnosis

Veterinarians typically perform:

Basic Tests:

• Urinalysis: pH, specific gravity, blood, protein, crystals
• Urine culture: to check for bacterial infection
• Blood work: kidney function, electrolytes

Imaging:

• X-rays: to check for stones in bladder and urethra
• Ultrasound: can detect small stones invisible on X-ray and assess bladder wall thickness

Treatment Options

Treatment depends on the underlying cause and severity.

Conservative Management

For mild symptoms or FIC patients, conservative treatment may include:

1. Dietary Changes

Increasing water intake is the most important intervention.

• Switch to wet food (moisture content >70-80%)
• Use water fountains to encourage drinking
• Add water to dry food

2. Prescription Diets

For different stone types, your vet may recommend urinary prescription diets:

For Struvite:

• Low magnesium, low phosphorus formulation
• Urine acidification (target pH < 6.4)
• Common brands: Hill’s c/d, Royal Canin S/O

For Calcium Oxalate (prevention):

• Moderate restriction of calcium and oxalate
• Mild urine alkalinization (target pH 7.0-7.5)
• Avoid high-oxalate foods (spinach, beets, peanuts)

3. Environmental Management (MEMO)

For FIC patients, Multimodal Environmental Modification has been proven effective at reducing recurrence:

• Provide enough litter boxes (number of cats + 1)
• Place litter boxes in quiet, private locations
• Provide vertical space (cat trees, window perches)
• Use pheromone diffusers
• Maintain consistent routines

4. Medications

• Pain relief: FIC is painful; analgesia is important
• Antispasmodics (Prazosin): relaxes urethral smooth muscle, though research shows mixed results
• Anti-anxiety medications: may help stress-related FIC

Catheterization

When a male cat develops urethral obstruction, emergency catheterization is required.

Procedure:

1. Stabilize Vital Signs

   • Establish IV access
   • Check blood electrolytes (especially potassium)
   • Treat life-threatening hyperkalemia if present

2. Bladder Decompression

   • The vet may perform cystocentesis (drawing urine from the bladder with a needle through the abdomen) to relieve pressure

3. Catheterization

   • Performed under sedation or general anesthesia
   • A lubricated catheter is gently passed through the obstruction
   • Generous saline flushing to dislodge the blockage

4. Indwelling Catheter

   • Usually left in place for 24-48 hours
   • Connected to a closed collection system
   • Recent research suggests urine color and clarity may be better indicators for removal than fixed timeframes

Post-procedure Care:

• Continued IV fluid therapy
• Monitor urine output and quality
• Prophylactic antibiotics NOT recommended (unless there’s evidence of infection)
• E-collar to prevent licking

Struvite Dissolution Therapy

If struvite stones are confirmed and located in the bladder, dietary dissolution can be attempted:

Protocol:

1. Transition to dissolution prescription diet (at least 1 week transition period)
2. Re-X-ray every 2-4 weeks to confirm stones are shrinking
3. Continue feeding for 30 days after stones are no longer visible on X-ray
4. Small stones may dissolve in 1-2 weeks; larger ones may take 2-3 months

Important Notes:

• Dissolution diets only work for struvite, NOT calcium oxalate
• If UTI is present, it must be treated simultaneously
• No other foods or treats during the dissolution period

Surgical Treatment

Cystotomy (Bladder Surgery)

When stones cannot be dissolved (like calcium oxalate), or are too large, too numerous, or causing repeated obstruction, surgical removal from the bladder may be necessary.

Perineal Urethrostomy (PU Surgery)

PU surgery is the “last resort” for male cats with recurrent urethral obstruction.

What is PU Surgery?

This procedure removes the narrowest part of the male cat’s urethra (within the penis) and sutures the wider pelvic urethra directly to the skin, creating a new, permanent urinary opening. Essentially, it bypasses the area most prone to blockage.

Indications:

• Recurrent urethral obstruction (2 or more times)
• Obstruction that cannot be relieved by catheterization
• Severe urethral trauma

Surgical Procedure:

1. General anesthesia
2. Removal of the penis and narrow urethral segment
3. The wider urethra is sutured to perineal skin
4. Hospital observation for several days post-surgery

Recovery:

• E-collar for 10-14 days to prevent licking
• Activity restriction
• Dust-free litter (like paper litter) to prevent wound infection
• Regular follow-up visits to monitor healing

Success Rate and Prognosis:

Preventing Recurrence

FLUTD has high recurrence rates. Studies show urethral obstruction recurrence ranges from 11-58% at various follow-up points. Prevention is more important than treatment.

Increase Water Intake

This is the most important preventive measure. Dilute urine means lower crystal concentration.

• Feed wet food: Wet food has 4-5 times more water than dry food
• Multiple water sources: Place water bowls in different locations
• Water fountains: Running water appeals to many cats
• Fresh water: Change daily

Dietary Management

• Follow your vet’s recommendations for appropriate prescription or maintenance diets
• Avoid high-magnesium, high-phosphorus treats
• For cats prone to calcium oxalate, avoid high-oxalate foods

Environmental Management

• Adequate litter boxes, kept clean
• Reduce environmental stressors
• Provide environmental enrichment
• Maintain consistent routines

Regular Monitoring

• Periodic urinalysis
• Regular X-ray follow-up if there’s a history of stones
• Watch for changes in urination behavior

Summary

FLUTD is a complex group of diseases requiring individualized treatment based on specific causes. Key takeaways:

1. Urethral obstruction is an emergency—especially for male cats, difficulty urinating requires immediate veterinary attention
2. Different stones need different treatments—struvite can be dissolved with diet; calcium oxalate requires surgery
3. PU surgery is a last resort—it solves obstruction but doesn’t cure the underlying cause
4. Prevention beats treatment—increase water intake, appropriate diet, and stress reduction are key
5. Regular follow-up—FLUTD tends to recur and requires long-term management

If your cat has had urinary tract issues, discuss a long-term management plan with your veterinarian. Every cat is different and needs an individualized care approach.