First Report of Heartworm (Dirofilaria Immitis) Infection in an Imported Dog in Lithuania

Over the past decade, increasing numbers of autochthonous cases of heartworm infection have been reported in the countries of Eastern Europe where previously only imported cases were described. In this report we have described the first clinical case of Dirofilaria immitis infection in an imported dog in Lithuania. In 2018, a 5-year-old male Spanish greyhound (Spanish galgo) was imported to Lithuania from southern Spain and referred to a small animal veterinary clinic in Vilnius for wellness screening. Circulating microfilariae and female antigens of D. immitis were detected using the Knott's test and SNAP 4Dx Plus Test (IDEXX Laboratories, Portland, USA). The diagnosis was confirmed using molecular analysis. Treatment according to the guidelines recommended by the American Heartworm Society was applied. This is the first confirmed report of canine heartworm infection in an imported dog in Lithuania. Heartworm-infected dogs transported to North-Eastern Europe from endemic areas could act as microfilarial reservoirs for the local mosquito population, which could increase the risk of spreading the disease.