🧬 Vet Guide 2025: Bladder Stones (Oxalate) in Dogs – Prevention, Treatment & Breed Risks 🐶💧

By Dr Duncan Houston, BVSc

🔍 What Are Bladder Stones (Oxalate)?

Bladder stones, or uroliths, are mineral deposits that form inside the urinary bladder. One of the most common types in dogs is the calcium oxalate stone, which cannot be dissolved by diet and often requires surgical or procedural removal. These stones frequently recur and need long-term prevention strategies. 🧪

🧬 Which Dogs Are at Risk?

73% of oxalate stone patients are male, and the condition typically affects dogs between ages 5 and 12. Breeds at higher risk include:

• 🐾 Miniature Schnauzers
• 🐾 Lhasa Apsos
• 🐾 Yorkshire Terriers
• 🐾 Miniature Poodles
• 🐾 Shih Tzus
• 🐾 Bichon Frises (extremely high recurrence rate)

🧪 How Are Oxalate Stones Diagnosed?

Stones are usually detected via radiographs (X-rays) or ultrasound. To determine the exact stone type, a stone must be retrieved and analyzed in a lab. Retrieval can be done via:

• 💦 Voiding urohydropropulsion (flushing small stones)
• 🔪 Surgery (cystotomy)
• 🔬 Cystoscopy or laparoscopic techniques (PCCL)

📉 Why Do Dogs Form Calcium Oxalate Stones?

Causes vary but commonly include:

• 🧬 Genetic defects (e.g. nephrocalcin deficiency)
• 💊 Antibiotic disruption of gut bacteria that metabolize oxalate
• 🍽️ Diets high in calcium, vitamin D, C, or oxalate-rich foods
• 🦠 Metabolic diseases like Cushing's or hypercalcemia

⚠️ Why Can’t the Stones Stay in the Bladder?

Leaving stones untreated can result in:

• 🚫 Urinary obstruction (especially in males)
• 😖 Painful irritation and bleeding
• 🦠 Chronic bladder infections
• 💀 Uremic poisoning or life-threatening blockages

🔧 Treatment Options

Because oxalate stones cannot be dissolved by diet, they must be physically removed. Options include:

• 🔪 Cystotomy (surgical removal)
• 🔬 PCCL (laparoscopic removal)
• 💡 Laser lithotripsy (breaks stones into passable pieces)

🛡️ Long-Term Prevention Plan

Step 1: Diet Modification

Special diets reduce urinary calcium and oxalate levels, and modify pH to discourage stone formation. Canned food is preferable to dry due to higher water content. Avoid:

• 🥬 Spinach
• 🍫 Chocolate
• 🥜 Peanuts
• ☕ Tea
• 💊 Vitamin C or D supplements

Approved treats include: plain cooked chicken, turkey, eggs, rice, peas, pasta, potatoes, cabbage, cauliflower, bananas, and melon.

Step 2: Monitoring with Urinalysis & X-rays

Every 3–6 months, check:

• 🔬 Urine pH and specific gravity
• 🧬 Presence of crystals
• 🩻 X-rays to monitor stone recurrence

Step 3: Potassium Citrate Supplementation

This supplement increases urinary citrate, which binds calcium (preventing oxalate bonding), and helps raise urine pH above 6.5. Usually given twice daily.

Step 4: Recheck & Adjust

Two to four weeks after starting potassium citrate, recheck urinalysis. If pH is still low or crystals persist, adjust hydration or diet. If needed, proceed to Step 5.

Step 5: Thiazide Diuretics

This diuretic class reduces urinary calcium excretion and is used when all other measures have failed. Electrolytes should be monitored after starting.

🩺 Special Considerations for Bichon Frise

This breed has a 20x increased risk of recurrence. In one study:

• 🔁 37% recurred in year 1
• 🔁 57% recurred in year 2
• 🔁 73% recurred in year 3

Prevention should begin immediately after surgery in this breed.

🧨 Preventing Male Obstruction

Male dogs have a bone (os penis) that prevents the urethra from stretching, making blockage life-threatening. A urethrostomy surgery may be performed to create a wider, lower-risk urinary opening in neutered males with repeat obstructions.

💡 What About Laser Lithotripsy?

Laser lithotripsy is a minimally invasive way to break up stones into passable pieces. Ideal for:

• 🪨 A small number of stones
• 🚫 Stones lodged in the urethra

It's faster and less invasive than surgery but may not suit dogs with dozens of stones.

🩺 Final Thoughts from Dr Duncan Houston

Calcium oxalate bladder stones can be frustrating. They're painful, expensive to treat, and highly likely to return—especially in high-risk breeds. But with diligent prevention, proper diet, and regular monitoring, many dogs live comfortably without repeat surgeries.

Prevention is far less costly and painful than emergency treatment. Work closely with your vet to create a monitoring and prevention plan that fits your pet’s unique needs. 🐶💧

📲 Need Help Creating a Stone Prevention Plan? Ask A Vet

Don’t wait until stones return. Get expert help with custom prevention, diet tips, and supplement advice. Download the Ask A Vet app to chat live with Dr Duncan Houston and other veterinary pros today. 🐾💬