Feline Urethral Obstruction Treatment

Alright, colleague. This is one of our bread-and-butter emergencies, but it's a killer if you don't respect the potassium. Let's walk through it.

Priority one: The heart. Forget the bladder for a minute; hyperkalemia will kill this cat. Get an ECG on him immediately. You're looking for bradycardia, peaked T waves, a widened QRS complex, and eventually, loss of the P wave.

Stabilization Protocol (The ABCs):

IV Access: Get a catheter in. Start with 0.9% NaCl or another potassium-free crystalloid. A 5-10 mL/kg bolus is a good place to start while you get your diagnostics.

Treat the Hyperkalemia: If K+ is >7 mEq/L or you see those ECG changes, act fast.

Calcium Gluconate 10%: 0.5-1.0 mL/kg IV slow over 10-15 minutes. This is cardioprotective; it raises the threshold potential but does not* lower potassium. Monitor the ECG during administration.
* Insulin/Dextrose: Regular insulin 0.25 U/kg IV followed by 1-2 grams of dextrose per unit of insulin. This drives potassium into the cells.

Analgesia/Sedation: These cats are incredibly painful. Butorphanol (0.2 mg/kg) is a good start. For unblocking, I prefer a combination of alfaxalone or ketamine/midazolam. Avoid dexmedetomidine in a hemodynamically unstable patient.

Unblocking and Post-Obstructive Management:
Once he’s more stable, unblock him. Place a closed-collection system and monitor urine output (UOP) closely. Post-obstructive diuresis (POD) is expected and can be massive. The goal is to match "ins and outs" after rehydration is complete, plus insensible losses (around 20 mL/kg/day). You may be running fluids at 2-3x maintenance initially. Monitor electrolytes, especially potassium and calcium, every 4-6 hours. Wean fluids as the POD resolves, typically over 24-48 hours.

This covers the immediate medical stabilization. The long-term management, especially for a repeat offender, is a surgical conversation.

James, I'll hand it over to you to discuss the indications and technique for a perineal urethrostomy once this cat is stable.

Marcus will cover the critical stabilization, as that's squarely in his court. My role as the surgeon comes into play once the cat is stable and we're discussing long-term prevention, particularly if this is a repeat offense.

I typically recommend a perineal urethrostomy (PU) for cats with recurrent obstructions (the classic "third strike"), those who develop a urethral stricture from catheterization trauma, or cases where we simply cannot pass a catheter. It's a salvage procedure, not a cure for the underlying cause of their FLUTD.

The goal of the surgery is to create a permanent, wider urethral stoma by bypassing the narrow penile urethra. Meticulous surgical technique is non-negotiable to prevent the primary and most devastating complication: stricture. The key is careful dissection to the level of the bulbourethral glands, which exposes the wider-diameter pelvic urethra. I then perform a dorsal urethrotomy and precisely anastomose the urethral mucosa to the perineal skin with fine-gauge (5-0 or 6-0) monofilament absorbable suture. Tension-free apposition is critical.

When counseling the owner, I'm very direct about the trade-offs. We are preventing future life-threatening blockages, but we are also shortening the urethra, which removes a natural barrier to infection. These cats have a higher risk of ascending bacterial cystitis for the rest of their lives. Post-operatively, an E-collar is absolutely mandatory for 10-14 days to prevent self-trauma and dehiscence of the surgical site.

A well-performed PU can be life-saving for these chronic blockers, but it doesn't eliminate the need for ongoing medical and dietary management of their underlying disease. That remains a critical component of their long-term care.