Survival outcomes, low awareness, and the challenge of neglected leptospirosis in dogs

Background: Leptospirosis is a globally neglected zoonotic disease with significant morbidity and mortality in dogs, particularly in resource-limited settings. Aim: This study aimed to characterize prognostic factors and survival outcomes in dogs with suspected leptospirosis, emphasizing the potential underestimation of disease burden. Methods: This retrospective study was conducted using medical records of dogs diagnosed with urinary Leptospira polymerase chain reaction (PCR). Results: Urinary Leptospira PCR was positive in 22 dogs and negative in 62. Azotemia was present in approximately two-thirds of both groups, with no predictive value identified between PCR-positive and PCR-negative dogs. However, PCR-positive dogs exhibited significantly shorter survival times for both all-cause mortality (median 60 days, range: 8–601 days) and leptospirosis-related death (median 27 days, range: 8–67 days) compared to PCR-negative dogs (median 402 days, range: 7–812 days) (p < 0.01). The neutrophil-to-lymphocyte ratio (NLR) in-dependently predicted leptospirosis-related death (HR = 1.073, 95%CI: 1.02–1.13, p = 0.01), while the BUN-to-creatinine ratio predicted all-cause mortality (HR = 1.02, 95% CI: 1.003–1.03, p = 0.02). Conclusion: Our findings underscore the severity of leptospirosis in older dogs, particularly those with azotemia or positive PCR results. NLR and BUN to creatinine ratios could be valuable tools for risk assessment and guiding treatment strategies in this vulnerable population.