Incidental Finding of Dirofilaria immitis (Spirurida: Onchocercidae) Microfilariae in the Bone Marrow of a Dog with Mixed Leishmania infantum-Dirofilaria immitis Infection

Canine leishmaniasis and cardiopulmonary dirofilariasis are common parasitoses in dogs and are endemic in various regions of Italy. Although Leishmania infantum and Dirofilaria immitis have commonly been reported as single infections in dogs in Italy, mixed infection with both parasites is seldom reported. This case report describes a very rarely reported localization of Dirofilaria immitis microfilariae in the bone marrow of an adult dog, which was serologically and PCR-positive for Leishmania infantum. This is the second reported case of the localization of D. immitis microfilariae in the bone marrow of a Leishmania-infected dog.