Not Every Feline Urolith Needs Surgery: Choosing the Right Treatment Strategy

Managing feline urolithiasis extends beyond identifying urinary stones—it requires selecting the most appropriate treatment for the individual patient. While surgery is often considered the default option, not every urolith requires immediate surgical removal. Stone composition, location, size, degree of obstruction and the cat's overall clinical condition all influence treatment decisions. An evidence-based approach helps avoid unnecessary procedures while ensuring timely intervention when required¹˒². 

Begin with Patient Stabilisation 

Before deciding how to remove a stone, clinicians should determine whether the cat is stable. Cats presenting with urethral obstruction, severe dehydration, electrolyte abnormalities or post-renal azotemia require immediate stabilisation before definitive treatment is attempted². 

Assessment should include: 

• Hydration status 

• Serum electrolytes 

• Blood urea nitrogen (BUN) and creatinine 

• Pain assessment 

• Bladder size and integrity 

Failure to correct metabolic abnormalities before intervention may increase anaesthetic and surgical risk². 

Clinical Pearl: Treat the patient before treating the stone. 

Identify the Stone Before Choosing the Treatment 

Treatment should never be based solely on the presence of a urinary stone. Whenever possible, clinicians should predict stone composition using signalment, urinalysis, imaging characteristics and clinical history before selecting therapy¹. 

This distinction is critical because: 

• Struvite uroliths may respond to therapeutic dissolution diets under appropriate clinical conditions¹. 

• Calcium oxalate uroliths do not dissolve medically and generally require physical removal¹. 

Attempting dietary dissolution of calcium oxalate stones delays definitive treatment and may increase the risk of persistent clinical signs or obstruction. 

When Is Medical Management Appropriate? 

Medical dissolution is most successful when: 

• Struvite urolithiasis is strongly suspected. 

• There is no urethral obstruction. 

• The patient is clinically stable. 

• Owners are likely to comply with dietary recommendations and follow-up imaging¹. 

During dissolution therapy, repeat radiographic evaluation is essential to confirm reduction in stone size and ensure treatment remains effective¹. 

Clinical Pearl: Medical dissolution requires monitoring—not simply changing the diet. 

When Surgery Is the Better Option 

Surgical intervention remains the treatment of choice for: 

• Calcium oxalate uroliths. 

• Large bladder stones unlikely to dissolve. 

• Persistent clinical signs despite medical management. 

• Recurrent urinary obstruction. 

• Cases where stone composition is uncertain and immediate removal is indicated¹˒². 

Cystotomy continues to be the most commonly performed procedure for bladder urolith removal and provides the added advantage of recovering intact calculi for quantitative stone analysis². 

Managing Urethral Uroliths 

Urethral calculi require rapid intervention because complete obstruction can quickly become life-threatening. Initial management often involves careful catheterisation with retrograde urohydropropulsion, allowing stones to be flushed back into the bladder before cystotomy². 

If urohydropropulsion is unsuccessful or catheterisation cannot be achieved, urethrotomy or referral for advanced intervention may be necessary². 

Clinical Pearl: Whenever feasible, relocate urethral stones into the bladder rather than attempting direct urethral removal. 

Stone Removal Is Only Half the Treatment 

Successful surgery does not eliminate the risk of recurrence. Every retrieved urolith should be submitted for quantitative analysis because prevention strategies depend on knowing the stone's mineral composition¹. 

Long-term management should include: 

• Therapeutic nutrition tailored to stone type. 

• Encouraging increased water intake. 

• Periodic urinalysis. 

• Follow-up imaging to detect early recurrence. 

• Investigation of metabolic disorders such as hypercalcaemia in cats with calcium oxalate urolithiasis¹. 

Failure to identify and address underlying risk factors increases the likelihood of recurrent disease. 

Take-Home Message 

There is no universal treatment for feline urolithiasis. The best outcomes are achieved when clinicians individualise therapy based on stone composition, anatomical location and the patient's clinical status. While medical dissolution is an excellent option for selected struvite stones, calcium oxalate calculi and obstructive uroliths generally require surgical intervention. Regardless of the treatment chosen, stone analysis and long-term preventive strategies remain essential to minimise recurrence and improve patient outcomes. 

References 

1. Bartges JW. Feline calcium oxalate urolithiasis: risk factors and rational treatment approaches. Journal of Feline medicine and Surgery. 2016 Sep;18(9):712-22. https://journals.sagepub.com/doi/full/10.1177/1098612x16660442
2. Yaygıngül R. Clinical, laboratory, radiography and ultrasonography findings and surgical treatment the lower urinary system urolithiasis in cats and dogs. Animal Health Production and Hygiene. 2024 Jun 6;13(1):23-30. https://dergipark.org.tr/en/download/article-file/3472658