Renal Amyloidosis in Dogs: A Retrospective Study of 91 Cases with Comparison of the Disease between Shar-Pei and Non-Shar-Pei Dogs

Background: Renal amyloidosis (RA) is a progressive and fatal renal disease. Hypothesis: Clinical and pathologic manifestations of RA differ between Chinese Shar-Pei (CSPs) and non-Shar-Pei (NSPs) dogs. Animals: 91 client-owned dogs. Methods: Retrospective review of medical records of dogs with a histological diagnosis of RA. Clinical and clinicopathologic data, hospitalization, complications, and outcome were compared between CSPs and NSPs. Results: Comorbid diseases were present in 64% of all dogs. CSPs were significantly younger compared to NSPs (median, 4.8 years; range: 3.6-17 versus median: 9.0 years; range: 2.4-11.1; P < .0001). The frequency of hypoalbuminemia, the most common biochemical abnormality, was higher in NSPs compared to CSPs (100% versus 64.7%, respectively; P < .001). Median serum creatinine concentration at presentation was 5.5 mg/dL, and was 3-fold higher in CSPs compared to NSPs (P = .005). Increased urine protein: creatinine ratio was present in 96% of all dogs. Nephrotic syndrome was present in 10% of NSPs but not in CSPs. Glomerular amyloid deposition, present in both CSPs (78.6%) and NSPs (95.6%) was most commonly diffuse, global, and severe. Renal medullar amyloidosis was more common in CSPs (100%) compared to NSPs (49.0%, P = .002), as was extrarenal amyloid deposition. The median survival time of all dogs was 5 days (range: 0-443 days). Serum creatinine concentration was significantly and negatively associated with survival (P = .025). Conclusions and Clinical Relevance: The clinical and pathologic manifestations of amyloidosis differ between CSPs and NSPs. The survival time observed herein was unexpectedly low, and argues for early surveillance and management of the underlying predisposing conditions.