Association between hyperadrenocorticism and development of calcium-containing uroliths in dogs with urolithiasis

Objective - To determine, among dogs with urolithiasis, whether dogs that had hyperadrenocorticism would be more likely to have calcium-containing uroliths than would dogs that did not have clinical evidence of hyperadrenocorticism. Design - Retrospective case-control study. Animals - 20 dogs that had urolithiasis and hyperadrenocorticism and 42 breed-matched dogs that had urolithiasis but did not have clinical evidence of hyperadrenocorticism. Procedure - Signalment, urolith composition, results of bacterial culture of urine, and results of adrenal axis tests were recorded. A multivariate logistic regression model was created, including terms for age, sex, and hyperadrenocorticism. The outcome variable was presence or absence of calcium-containing uroliths. Results - Among dogs with urolithiasis, those that had hyperadrenocorticism were 10 times as likely to have calcium-containing uroliths as were dogs that did not have clinical evidence of hyperadrenocorticism (odds ratio, 10.5; 95% confidence interval, 1.5 to 23.4). Neutered and sexually intact females were less likely to have calcium-containing uroliths than were neutered males (odds ratios, 0.041 [95% confidence interval, 0.0057 to 0.29] and 0.024 [95% confidence interval, 0.0012 to 0.5], respectively). Clinical Implications - Prompt diagnosis and treatment of hyperadrenocorticism may decrease prevalence of calcium-containing uroliths in dogs.