Canine Glomerular Disease Study Guide

Overview and Clinical Importance

Amyloidosis is a progressive and often fatal disease characterized by the extracellular deposition of insoluble fibrillar proteins (amyloid) in various organs. In dogs, the kidneys are the most commonly affected organ, with glomerular amyloidosis representing approximately 15% of all canine glomerular diseases. The condition results from misfolding of serum amyloid A (SAA) protein during chronic inflammatory states, leading to the accumulation of AA-type amyloid fibrils.

Understanding amyloidosis is critical for the NAVLE because it represents a distinct pathophysiological mechanism of protein-losing nephropathy that requires specific diagnostic approaches and has important breed predispositions. Unlike immune-complex glomerulonephritis, amyloidosis has no effective treatment to reverse protein deposition, making early recognition and supportive management essential.

Etiology and Pathophysiology

Types of Amyloidosis in Dogs

AA Amyloidosis (Reactive/Secondary): The most common form in dogs, arising from chronic inflammatory conditions. During persistent inflammation, hepatocytes produce serum amyloid A (SAA) as an acute phase protein. When inflammation is prolonged, SAA undergoes abnormal proteolytic processing and misfolds into insoluble beta-pleated sheet fibrils that deposit in tissues.