Dogs may carry Leishmania tropica and Leishmania major in their blood circulation: a molecular and hematological study

Background Dogs may be infected with species of leishmania parasites that are disseminated through the body by blood circulation and invade the internal organs. Therefore, in this study, we attempted to find out the parasite in the blood of dogs in an area where the disease is more identified as the cutaneous type of leishmaniasis. A total of 135 blood samples were taken from dogs (50 Anaemic and 85 normal) and subjected to PCR reaction using ITS-1 and ITS-2 regions of the ribosomal gene. Results Totally, seven samples (5.1%) were positive, six were identified as L. tropica and one sample was L. major . This result was interesting because we did not find any case of L. infantum which is always known for visceral infection. In addition, no sign of cutaneous lesions or a significant disease was seen in the animals infected with both species. From 48 dogs suffered from anemia, 2 cases were Leishmania positive. The mean value of hematological parameters in the infected dogs was within the normal range except for a significant reduction in the platelet measures (p < 0.05). Conclusions Our data revealed that both Leishmania species, tropica and major , may manifested by viscerotropic leishmaniasis. More investigations are needed to find the conditions that those species decide to select the type of infection. Moreover, our data emphasize the role of asymptomatic dogs to carry the Leishmania parasite.