Veterinary Guide to Canine Kidney Stones (Nephrolithiasis) 2025 🐶🩺

By Dr. Duncan Houston BVSc

🧬 What Are Kidney Stones?

Kidney stones (nephroliths) are hard mineral deposits—most commonly struvite, calcium oxalate, urate, or cystine forms—that develop within the kidney or ureter. Though rare compared to bladder stones, they can range from asymptomatic to life‑threatening when obstructive.

👥 Who’s at Risk?

• Toy & small breeds: Pomeranians, Yorkshire Terriers are overrepresented.
• Female dogs: Slightly higher incidence due to urinary anatomy.
• Underlying conditions: Dehydration, UTIs, metabolic disorders (IBD, diabetes), high-mineral diets increase risk.

⚠️ Signs to Watch For

Clinical signs depend on stone size, location, infection, and obstruction:

• Blood-tinged urine (hematuria), frequent urination or straining.
• Increased thirst, urination frequency, and small urine volume.
• Abdominal/back pain, intermittent vomiting, lethargy, weight loss.
• Obstruction signs: renal pain, vomiting, progression to acute kidney injury.
• Some stones remain clinically silent and are found incidentally.

🔍 Diagnostic Approach

1. History & exam: Attention to urinary changes, pain on palpation.
2. Bloodwork & urinalysis: Look for infection, crystal types, kidney markers.
3. Imaging:
   • X-rays to detect radiopaque stones (e.g., calcium oxalate); struvite may or may not be visible.
   • Ultrasound is ideal for small stones, ureteral stones, and hydronephrosis; see UI images above.
4. Contrast studies: Used when X-ray/ultrasound are inconclusive.
5. Stone analysis: Imperative post‑removal to guide preventive diet and therapy.

🛠️ Treatment Options

• Medical Management

• Hydration & diuretics to encourage stone passage.
• Dietary dissolution for struvite stones; not effective for oxalate stones.
• Antibiotics for concurrent UTIs.
• Pain relief and anti-inflammatories for comfort.

• Minimally Invasive Interventions

• Ureteral stenting or lithotripsy to break and pass stones.
• Hydropropulsion for small stones.

• Surgery

• Nephrotomy or ureterotomy/nephrectomy for large, obstructive, or non-functional kidneys.
• Risks: anesthesia, kidney trauma—balanced individually.

• Follow-up Care

• Reassess imaging and urinalysis every 3–6 months.
• Repeat stone analysis on recurrences to tailor diet/therapy.

📈 Prognosis

• Asymptomatic stones may remain stable with periodic monitoring.
• Dissolvable form (struvite) has good outcomes; oxalates often require invasive management.
• Obstructive and complicated stones pose a higher risk, may lead to permanent kidney damage or renal failure.

🏡 Prevention & Home Strategies

• Maintain fresh water to encourage dilute urine and prevent crystal formation.
• Use prescription diets targeted to stone type—struvite, oxalate, urate, cystine.
• Avoid excessive minerals in diet; monitor underlying health conditions.
• Regular wellness exams and urine monitoring for high-risk dogs.

📱 Ask A Vet Telehealth Support

• 📸 Upload ultrasound or X‑ray images and urine videos for remote evaluation.
• 🔔 Medication, diet, hydration reminders, and urine-tracking alerts.
• 🩺 Video consults to review signs, manage medications, and decide the need for advanced imaging.

🎓 Case Spotlight: “Milo” the Yorkie

Milo, a 4‑year‑old Yorkshire Terrier, had recurring hematuria. Ultrasound revealed two small struvite nephroliths. With a prescription diet, increased water intake, and antibiotics for a concurrent UTI, both stones dissolved within 10 weeks. Ask A Vet provided daily water intake goals, diet reminders, and check‑in scans. Six‑month follow‑up showed no recurrence. 🐾

🔚 Key Takeaways

1. Kidney stones in dogs can be silent or symptomatic: look for hematuria, pain, and urinary changes.
2. Diagnosis requires imaging and urinalysis: stone type dictates treatment.
3. Medical dissolution is possible for certain stones: struvite dissolves with diet; others need intervention.
4. Advanced care: minimally invasive procedures or surgery may be needed for obstructive stones.
5. Prevention: hydration, targeted diets, and managing health risks.
6. Ask A Vet telehealth supports remote evaluation, adherence, symptom monitoring, and care coordination 📲🐾

Dr Duncan Houston BVSc, founder of Ask A Vet. Download the Ask A Vet app to support your dog’s urinary health—from early detection to telehealth imaging review, diet delivery, and advanced care coordination 🐶📲