Leishmaniasis is a complex disease considered one of the most neglected tropical diseases of the world. The importance and role of domestic dogs and wild canids as a source of leishmaniasis infection is well recognized. The present mini-review discusses a series of epidemiological studies that reinforce the need to understand the role of reservoirs and vectors in the expansion of leishmaniasis to Brazilian urbanized areas, as Brazil is a country of continental dimensions and endemic for leishmaniasis. Emphasis isgiven on the diagnostic tools and treatment options that must be recognized as crucial options to prevent expansion of visceral leishmaniasis cases.