Sire’s role in vertical transmission of Leishmaniasis infantum to offspring

Leishmania infantum is one of the parasites that causes leishmaniasis throughout the Mediterranean region, as well as Central and South America. This disease is commonly spread by sand flies in these areas, taking the parasite from animals, commonly dogs, and infecting humans and other animals. Case reports in areas where this parasite is not common have reported the parasite spreading from dog-to-dog through sex and fighting, as well as blood transfusions and from parents to offspring. More recently L. infantum has spread to be found commonly within foxhounds around the United States, where no sand flies are known to be infected. Previous research has investigated how the dam’s diagnostic status impacts her offspring’s risk of becoming diagnostically positive for L. infantum, but none have looked into the sire.

Using previously collected data from samples collected and sent in for diagnostic testing between 2013 and 2022, analyses were conducted to analyze how the sire’s lifetime diagnostic status and the status during the year of birth impacted his offspring testing positive throughout their lifetime. While the results did trend toward the sire having an impact, more research is needed to confirm these results.

It is important to consider how breeding animals known to be infected with parasites that also thrive in humans impacts future generations. Taking precautions to prevent breeding infected animals prevents future spread of disease.