Vet’s 2025 Guide to Glucosuria in Dogs – Causes, Diagnosis & Care 🐶

By Dr. Duncan Houston BVSc

💡 What Is Glucosuria?

Glucosuria (or glycosuria) means glucose is present in a dog’s urine—normally all filtered glucose is reabsorbed by the kidneys. Its presence often flags an underlying issue such as diabetes mellitus or renal dysfunction.

⚠️ Who’s at Risk & Why?

• Hyperglycemic glucosuria: Blood glucose exceeds ~180 mg/dL, common in diabetes, Cushing’s, pancreatitis, stress, or drug use (steroids, epinephrine).
• Normoglycemic (renal) glucosuria: Glucose in urine despite normal blood sugar, often due to Fanconi syndrome or inherited tubular defects (Scottish terriers, Basenjis, etc.).

🔍 Signs & Clinical Clues

• Excessive drinking & urination (polydipsia/polyuria), diluted urine.
• If due to diabetes: weight loss, ravenous appetite, cataracts, frequent infections.
• With renal causes: possible metabolic issues, electrolyte imbalance, weak urine concentrating ability.

🧪 How It’s Diagnosed

• Urinalysis & dipstick: Detect glucose; may require multiple samples due to intermittent shedding.
• Blood tests: Fasting blood glucose, CBC, chemistry; confirm hyperglycemia in diabetes.
• Serum fructosamine: Helps differentiate persistent normoglycemia from diabetes-related glucosuria.
• Advanced tests: Glucose tolerance test, breed-targeted tests (e.g., Fanconi syndrome), kidney imaging, biopsy in renal disease suspicion.

💊 Treatment & Management

• Address underlying cause: Diabetes treated with insulin & dietary therapy; endocrine or pancreatic causes managed accordingly.
• Renal glucosuria: Usually benign; Fanconi syndrome requires lifelong management of electrolytes, fluids, and nutrition.
• Stop triggering drugs: Remove steroids, glucose infusions, or toxins if identified.
• Supportive care: Rehydration, monitor electrolytes, treat infections or complications.

📈 Follow-Up & Monitoring

• Frequent blood glucose checks in diabetic dogs—home or clinic-based curves for dose adjustments.
• Periodic urinalysis and biochemical panels to track renal or electrolyte status.
• Serum fructosamine monthly in early diabetes management.
• Breed-specific monitoring for known inherited glucosuria conditions.

🛡️ Long-Term Outlook

With proper diagnosis and treatment:

• Diabetic dogs can live long, healthy lives with insulin and diet control.
• Primary renal glucosuria often has excellent outcomes without specific therapy.
• Fanconi syndrome prognosis varies—early detection and electrolyte support improve quality of life.

📲 Owner Tools & Support

• Ask A Vet – real-time telehealth help with diagnosis, dosing, and monitoring plans.

🌟 Case Example

Case: Max, a 4-year-old Scottish Terrier, was found to have glucosuria during a routine exam but normal blood glucose. Fructosamine and breed screening confirmed primary renal glucosuria. No treatment was needed; annual monitoring ensures kidney health remains stable. 🐶

✅ Final Takeaways

• Findings of glucose in urine require further testing—not all cases are diabetes.
• Blood tests, fructosamine, and urine monitoring help differentiate causes.
• Management varies: insulin & diet for diabetes, supportive care for renal causes.
• Monitoring and early intervention can ensure excellent outcomes.

📥 Get Expert Support

Download the Ask A Vet app for live guidance on glucosuria, diabetes care, or kidney function monitoring. Visit AskAVet.com for 24/7 vet access. 🐾🩺