Chronic Kidney Disease in Dogs: What You Need to Know

The kidneys filter waste products from the blood, regulate fluid balance, and produce hormones that stimulate red blood cell production. In chronic kidney disease (CKD), kidney function declines progressively — often silently until 75 % of function is already lost. By then, compensation mechanisms are exhausted and symptoms can deteriorate quickly.

Symptoms

• Polydipsia and polyuria — increased drinking and urination, often the earliest sign
• Weight loss and reduced appetite
• Vomiting — especially in the morning, often bile
• Lethargy and weakness
• Bad breath — uraemic odour, described as ammonia or chemical smell
• Pale gums — from anaemia (reduced erythropoietin production)
• Mouth or stomach ulcers in advanced stages

Diagnosis and Staging

Blood chemistry (creatinine, BUN, phosphate), urinalysis (urine specific gravity — dilute urine is a critical early sign), and SDMA (a sensitive early marker that can detect CKD when creatinine is still normal). The IRIS (International Renal Interest Society) staging system classifies CKD into 4 stages, each with different treatment targets.

Blood pressure measurement is essential — hypertension is common in CKD and accelerates renal damage.

Management

• Renal diet: reduced phosphorus, controlled protein (quality over quantity), increased moisture — wet food significantly increases daily water intake
• Phosphate binders when phosphate is elevated (aluminium hydroxide, sevelamer)
• Antihypertensives if hypertension is present (benazepril, amlodipine)
• Erythropoiesis-stimulating agents (darbepoetin) for significant anaemia
• Anti-nausea medication to maintain appetite
• Adequate hydration: always fresh water; subcutaneous fluids at home for advanced stages — many owners learn to do this themselves

Track water intake, body weight, and lab results in Purzi. Month-on-month trends reveal whether treatment is stabilising function or whether disease is progressing — and help you and your vet make timely adjustments.