Glucosuria in Dogs
Glucosuria, also known as glycosuria, refers to the elimination of glucose through the urine. Typically, the kidneys efficiently reabsorb all filtered glucose back into the bloodstream. Glucosuria commonly indicates kidney disorders, primarily diabetes mellitus, where this reabsorption process is compromised.
Symptoms and Types
Glucosuria is classified as hyperglycemic (170–220 mg/dL) or normoglycemic, and further subcategorized as transient or persistent. Clinical manifestations vary depending on the underlying condition, but potential signs encompass:
- Diluted urine
- Elevated thirst and increased drinking (polydipsia and polyuria, respectively)
- Renal failure (particularly in cases associated with Fanconi’s syndrome)
- Urinary tract disease
- Potential systemic illness (in instances of hyperglycemic glucosuria)
Causes
Hyperglycemic glucosuria
- Transient
- Hyperglycemia due to stress
- Adverse reactions to drugs (e.g., epinephrine, morphine, and phenothiazines)
- Persistent
- Underlying systemic diseases
- Diabetes mellitus
- Excessive adrenal gland activity (hyperadrenocorticism)
- Acute inflammation of the pancreas (acute pancreatitis)
- Lesions in the central nervous system (brain, spine, etc.)
- Adrenal gland tumors (pheochromocytoma)
- Hyperglycemia associated with progesterone
- Bacterial bloodstream infections (sepsis)
- Glucagonoma (pancreatic tumor producing glucagon, a hormone that raises blood sugar levels)
- Chronic liver failure
- Causative agents like heavy metal poisoning, drugs, and chemicals
Normoglycemic glucosuria
- Congenital normoglycemic glucosuria
- Primary renal glucosuria (found in Scottish terriers and mixed-breed dogs)
- Congenital Fanconi’s syndrome (seen in basenji, Norwegian elkhound, miniature Schnauzer)
- Congenital diseases related to kidney dysfunction (Norwegian elkhound)
- Acquired normoglycemic glucosuria
- Sudden kidney failure
- Fanconi’s syndrome secondary to heavy metal poisoning, drugs, and chemicals
Diagnosis
Provide your veterinarian with a detailed history of your dog’s health, including the onset and characteristics of the symptoms. Your veterinarian will conduct a comprehensive physical examination and order a complete blood count, biochemistry profile, electrolyte panel, and urinalysis to identify any underlying systemic diseases causing glucosuria. However, detecting glucose in the dog’s urine can be challenging due to low levels. Quantification of urinary glucose is typically done using hexokinase- or glucose dehydrogenase-based techniques.
Treatment
The treatment approach will vary based on the underlying cause of glucosuria. In cases of urinary tract infections, antibiotics will be prescribed and adjusted based on culture results. Additionally, any solutions or medications implicated in causing glucose to appear in the urine should be promptly discontinued.