Graduate student University of Minnesota Falcon Heights, MN, United States
Background – Nephrocalcinosis and nephrolithiasis are common findings in feline kidneys, but their relationship to each other remains poorly understood. Understanding these associations is essential for developing effective therapeutic approaches to feline nephrocalcinosis and nephrolithiasis. Hypothesis/Objectives – To evaluate the co-occurrence between nephrocalcinosis and nephrolithiasis in feline kidneys. Animals – Kidneys from 175 client-owned cats were collected post-mortem within 24 hours of euthanasia. Methods – In this cross-sectional study, high-resolution microradiography was used to classify nephrocalcinosis patterns in kidneys with and without nephroliths. Nephroliths from select kidneys were retrieved for validation and compositional analysis (IR). Fisher’s exact and chi-square tests were used to assess associations. Logistic regression was used to evaluate predictors of nephrolithiasis. Results – Nephrocalcinosis was observed in 84% (147/175) of cats, and nephroliths were identified in 54.3% (95/175). 59.5% of cats with nephrocalcinosis had nephroliths, compared to 25% of cats without nephrocalcinosis (χ² = 10.2, p = 0.001). 350 kidneys were independently evaluated; 92.7% (267) has striated nephrocalcinosis, 26% (75) had punctate nephrocalcinosis, and 17.7% (62) without nephrocalcinosis; nephroliths were identified in 49%, 53%,and 12.9% respectively. In univariate analysis, nephrocalcinosis was associated with a high risk of nephrolithiasis (OR = 3.45, 95% CI = 1.60–7.44, p = 0.002, n = 175). Cat age was a significant risk factor for nephrolithiasis (OR = 1.15, 95% CI = 1.05–1.25, p = 0.001, n = 115). Conclusions and Clinical Importance – Nephrocalcinosis is a significant risk factor for nephrolithiasis. The underlying shared pathology requires further study.
