Filarioids infecting dogs in northeastern Brazil

Species of filarial nematodes belonging to the genera Dirofilaria and Acanthocheilonema are recognisedas common parasites of dogs throughout the world. Recently, other filarioids featured by the presenceof dermal microfilariae (e.g., Onchocerca lupi and Cercopithifilaria spp.) have been recognised in Europe.In Brazil, reports of filarioids in dogs are limited to Dirofilaria immitis, Acanthocheilonema reconditum andCercopithifilaria bainae. To investigate the distribution of filarial infections in dogs living in an endemicregion from northeastern Brazil, blood and skin samples (n = 104) were microscopically (modified Knott’stest and skin snip sediment examination) and molecularly evaluated. Twenty-two dogs (21.15%) werepositive at microscopic and/or molecular examination for at least one filarioid species, with 21 (20.19%)animals positive for blood microfilariae at molecular and/or at microscopic examination. Microfilariae ofD. immitis were detected in 12 (11.54%) animals, with co-infection of D. immitis and A. reconditum observedin four (3.85%) individuals. One animal was positive for C. bainae at both microscopic and molecularexamination. Analysis of sequence obtained in the present study showed significant alignment identitywith that of C. bainae from Europe. Considering that in the area of study arthropod vectors (mosquitoes,fleas and ticks) are prevalent throughout the year, preventive measures should be disposed in order toavoid the animal infestation and pathogen infection.