Affects: Dogs
Canine leishmaniasis (LEESH-ma-NIGH-ah-sis) is a zoonotic disease (see human leishmaniasis) caused by Leishmania parasites transmitted by the bite of an infected phlebotomine sandfly. There have been no documented cases of leishmaniasis transmission from dogs to humans. Canine leishmaniasis was first identified in Europe in 1903, and in 1940, 40% of all dogs in Rome were determined to be positive for leishmaniasis. Traditionally thought of as a disease only found near the Mediterranean basin, 2008 research claims new findings are evidence that canine leishmaniasis is currently expanding in continental climate areas of northwestern Italy, far from the recognized disease-endemic areas along the Mediterranean coasts. Cases of leishmaniasis began appearing in North America in 2000, and, as of 2008, Leishmania-positive foxhounds have been reported in 22 U.S. states and two Canadian provinces.
Cause: Numerous strains and subgenus strains of Leishmania exist; with sandfly genome projects still underway, strains are still being discovered.
In the Old World, leishmaniasis transmitted by sandflies of the genus Phlebotomus documented in dogs are:
L. donovani in Sri Lanka
L. infantum (began appearing dogs in the United States in 2000)
Diagnosis: In the United States, certain breed clubs are strongly recommending screening for Leishmania, especially in imported breeding stock from endemic locations. For reasons yet unidentified the Foxhound and Neapolitan Mastiff seem to be predisposed or at higher risk for disease. The Italian Spinone Club of America is also requesting all breeders and owners to submit samples for testing; the club reported 150 Spinone Italiano dogs have tested positive in the United States.
In the United States, the following veterinary colleges and government bodies assist with testing and treatment of Leishmania-positive dogs:
Centers for Disease Control and Prevention on Leishmaniasis in dogs
Treatment: Currently, no cure exists for canine leishmaniasis, but various treatment options are available in different countries. Treatment is best coordinated with veterinary research hospitals. Treatment does vary by geographic area, strain of infection and exhibited symptoms. Dogs can be asymptomatic for years. Most common treatments include:
L. donovani
Amphotericin B is recommended, antimony resistant
L. infantum
Prevention: In areas where the known vector is a sandfly, deltamethrin collars worn by the dogs has been proven to be 86% effective. The sandfly is most active at dusk and dawn; keeping dogs indoors during those peak times will help minimize exposure.
Unfortunately, there is no one answer for leishmaniasis prevention, nor will one vaccine cover multiple species. "Different virulence factors have been identified for distinct Leishmania species, and there are profound differences in the immune mechanisms that mediate susceptibility/resistance to infection and in the pathology associated with disease."
In 2003, Fort Dodge Wyeth released the Leshmune vaccine in Brazil for L. donovani (also referred to as kala-azar in Brazil). Studies indicated up to 87% protection. Most common side effects from the vaccine have been noted as anorexia and local swelling.