Influence of therapeutic protocols and clinicopathological parameters on survival of dogs with leishmaniasis

Visceral leishmaniasis (VL) is a neglected disease caused by the protozoan Leishmania infantum , characterized by high lethality and predominantly affecting populations in conditions of social vulnerability. In Brazil, domestic dogs are the main urban reservoirs, and the treatment of canine infection is debated due to the absence of parasitological cure and the high cost of treatment. This study aimed to evaluate the survival of dogs with canine leishmaniasis (LCan) treated with two therapeutic protocols and to assess the impact of clinical and laboratory variables on canine survival. This prospective observational cohort study was conducted with 71 dogs treated at the Veterinary Hospital of UFMT-Cuiabá. The dogs were treated with a combination of miltefosine and allopurinol or with allopurinol monotherapy and were clinically followed up and monitored through laboratory examinations. Survival curves were analyzed using the Kaplan–Meier method and Cox regression. The results showed that the combination of miltefosine and allopurinol was associated with higher survival compared with monotherapy, with a 720-day survival probability of 71.5% versus 46.5%, respectively. In the Cox regression with time-dependent covariates, an increased risk of death was associated with a body condition score ≤ 2, a clinical severity score ≥ 17, anemia, azotemia, hypoalbuminemia, and reduced albumin-to-globulin ratio. Thrombocytopenia and hyperglobulinemia were not associated with the risk of death. It is concluded that the body condition score, clinical severity score, anemia, azotemia, hypoalbuminemia, and decreased albumin-to-globulin ratio determine survival and prognosis. Low treatment adherence remains a challenge in LCan.