Canine Chronic Kidney Disease Study Guide

Overview and Clinical Importance

Chronic kidney disease (CKD) is defined as structural or functional kidney abnormalities persisting for at least three months, or a reduction in glomerular filtration rate (GFR) by more than 50% from normal for the same duration. CKD affects approximately 0.5% to 1.5% of all dogs and is a leading cause of morbidity and mortality, particularly in geriatric patients. The disease is characterized by irreversible, progressive loss of functional nephrons and eventual replacement fibrosis.

Etiology and Pathophysiology

Causes of Canine CKD

Pathophysiology of CKD Progression

Glomerular Hyperfiltration: When nephrons are lost, remaining nephrons increase their single-nephron GFR. This increases intraglomerular pressure, causing proteinuria, glomerulosclerosis, and progressive nephron destruction.

RAAS Activation: Angiotensin II vasoconstricts the efferent arteriole to maintain GFR but causes glomerular hypertension and promotes oxidative stress, inflammation, and fibrosis.