Helminth infracommunity in a maned wolf, Chrysocyon brachyurus, from the humid Chaco, Argentina

Parasitism is an important factor in conservation worldwide, especially for endangered species, as it can affect host populations by reducing growth rates, fecundity and affecting nutritional status. The maned wolf Chrysocyon brachyurus, a near-threatened species, is distributed across different habitats from the south Amazonian forest in Brazil to northern Argentina, Paraguay and eastern Bolivia. Most studies on gastrointestinal parasites in wild maned wolves are based on coprological findings, and there is little information about adult parasites and parasite species richness. Therefore, this study aims to expand the knowledge about the helminth infracommunity of a maned wolf, describe adult parasites, and explore parasitic coinfections. We performed a necropsy of an adult individual found road killed in Chaco province, Argentina. We collected adult worms from subcutaneous tissues, from the right ventricle, kidneys, and intestine. The parasites were morphologically identified as Dirofilaria immitis, Dioctophyma renale and Spirometra sp. respectively. To our knowledge, this is the first record for adults of Dirofilaria immitis in maned wolves. Filarioids were located within the heart as well as in subcutaneous tissues with mature females containing uterine microfilariae; this study also adds C. brachyurus as a new host for Spirometra sp. in Argentina. Considering that the three helminths found herein are zoonotic and that the maned wolf is an endangered canid, it is essential provide baseline information to determine the risk factors involved in the transmission and extend the studies to sympatric wild and domestic canids in the area.