Outcome and prognostic factors in infective endocarditis in dogs: 113 cases (2005-2020)

Background Factors associated with outcome in dogs diagnosed with infective endocarditis (IE) are not well characterized. Objectives Evaluate outcome and prognostic factors in dogs with IE. Animals One hundred and thirteen dogs with IE. Methods Medical records for dogs that fulfilled the modified Duke criteria between 2005 and 2020 were retrospectively reviewed. Signalment, preexisting conditions, clinicopathologic findings, treatment regimen, and outcomes were recorded. Univariate logistic regression was performed to identify categorical factors associated with mortality, and then multivariate analysis was performed. Results Dogs were categorized as survivors (n = 47), non-survivors (n = 57), or lost to follow-up (n = 9). Survival to discharge and at 1 month was documented in 79 (70%) of 113 and 56 (54%) of 104 dogs, respectively, with median survival time (MST) of 72 days. Risk factors associated with mortality included development of congestive heart failure (odds ratio [OR], 11.8; 95% confidence interval [CI], 1.4-97.8), thromboembolic events (OR, 5.7; 95% CI, 2.3-14.4), and acute kidney injury (OR, 6.2; 95% CI, 2.0-18.8). Administration of antithrombotic medications was associated with survival (OR, 0.35; 95% CI, 0.13-0.97). Dogs that were not treated with antithrombotics had MST of 92 days, whereas dogs treated with antithrombotics did not reach MST during the study period. The heart valves involved and etiologic agent identified did not correlate with outcome. Conclusion and Clinical Importance Dogs with IE that had thromboembolic events, acute kidney injury, or congestive heart failure had higher risk of mortality. Administration of antithrombotics was associated with prolonged survival time.