The identifying of the preferred breeding sites of sand fly immature forms is quite important to the understanding of the vector’s biology and the development of more effective control strategies for leishmaniasis. In the present study, it was analyzed experimentally; the potential of dog feces of serving as breeding substrate to Lutzomyia longipalpis. Two situations were tested: 1) the life cycle of the insects from larvae to adults, 2) the whole cycle from adults to adults. Our results demonstrated for the first time that: 1) L. longipalpis can be easily bred in dog feces, suggesting that it could represent a potential raising substrate to immature forms for this species; 2) L. longipalpis larvae are able to make galleries on a substrate, literally burying themselves in this to function also as a shelter; 3) from the previous information that dogs infected with Ancylostoma caninum can present dodecanoic acid in their feces, we suggested that this substrate may be particularly more attractive to L. longipalpis females seen that this molecule is the same component of their oviposition pheromone, which is produced by the accessory glands and secreted onto the eggs; 4) after the copulation the males may landing on the substrate and continued beating the wings intermittently until the death in a similar behavior also noticed in other situations associated to kairomones response or pheromone production. Therefore, we suggested that it is very likely that dog excrements could serve as an important breeding substrate for L. longipalpis in endemic areas of visceral leishmaniasis in the New World.