As previously reported by TheHorse.com, a rare, potentially fatal species of parasite never before found in North America was been identified in a Florida horse last year.

University of Florida (UF) veterinarians identified the parasite, Leishmania siamensis, in the summer of 2011. This particular species of parasite previously had been found only in Thailand and parts of Europe while other Leishmania species have been found all over the world. No Leishmania infections of any species had been previously reported in a horse native to the United States.

The UF discovery raises awareness of how widespread the parasite is and suggests a need for watchfulness regarding potential transmission to humans, the researchers said.

"We now know the parasites that cause this disease also exist here in the United States and that we have some insect, presumably the sandfly, that is capable of transmitting the disease," said Sarah Reuss, VMD, a clinical assistant professor of large animal medicine at the UF College of Veterinary Medicine, who, along with UF colleagues and a private practice clinical pathologist, described the findings in the September issue of Emerging Infectious Diseases, a journal of the Centers for Disease Control and Prevention. "Our findings raise several potential avenues of further investigation, including the prevalence of this disease in horses in the United States, a better understanding of the sandfly life cycle, and the potential of this leishmaniasis species to be transmitted from animals to humans