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

## TL;DR

This study finds that immune complex-mediated kidney disease is less common in dogs from Australia and New Zealand compared to the U.S. and Europe.

## Contribution

The study reports the first prevalence of immune complex-mediated glomerulonephropathy in Australian and New Zealand dogs with kidney disease.

## Key findings

- Only 30% of dogs had immune complex-mediated glomerulonephropathy, with membranous glomerulonephropathy being the most common subtype.
- Dogs with glomerulosclerosis were older and had higher serum albumin levels compared to those with membranous glomerulonephropathy.
- The lower ICGN prevalence may be due to fewer infectious diseases in Australia and New Zealand.

## Abstract

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.

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.

Fifty client‐owned dogs.

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.

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).

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.