Clinical and Pathologic Characterization of Proteinuric Kidney Disease in Australian and New Zealand Dogs.

Abstract

BACKGROUND: The prevalence of immune complex-mediated glomerulonephropathy (ICGN) in dogs with proteinuric kidney disease is approximately 50% in the United States and Europe but is unknown in other locations such as Australia and New Zealand. OBJECTIVES: Determine the prevalence of ICGN in dogs biopsied for proteinuric kidney disease in Australia and New Zealand and compare clinicopathologic variables in dogs with specific pathologic lesions. ANIMALS: Fifty client-owned dogs. METHODS: Retrospective case series. Reports from renal biopsy samples submitted to the Texas and International Veterinary Renal Pathology Services from dogs with proteinuric kidney disease (urine protein-to-creatinine ratio ≥ 0.5) between 2007 and 2023 were reviewed. Clinical data were retrieved and compared. RESULTS: Among 50 dogs with proteinuric renal disease, 15 dogs (30%) had ICGN and 35 (70%) had non-ICGN. The most common category of ICGN was membranous glomerulonephropathy (6/15; 40%). Glomerulosclerosis was the most common category of non-ICGN (17/35; 49%). Dogs with glomerulosclerosis (median, 10 years) were older than dogs with other types of lesions (membranoproliferative, mesangioproliferative or mixed pattern; median, 6 years; p = 0.04) and those with membranous glomerulonephropathy (median, 4 years; p = 0.005). Dogs with membranous glomerulonephropathy had lower serum albumin concentrations (median, 2.1 g/dL) than dogs with glomerulosclerosis (median, 3.0 g/dL; p = 0.01) or other nephropathies (median, 3.0 g/dL; p = 0.04). CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of ICGN is lower in dogs in Australia and New Zealand biopsied for proteinuric kidney disease, potentially because of a lower prevalence of infectious disease, particularly vector-borne disease. The lower prevalence of ICGN emphasizes the importance of renal biopsy to optimize treatment.