Clinical and Pathological Effects of Filariasis in Tayra ( <i>Eira barbara</i> ) and Crab‐Eating Fox ( <i>Cerdocyon thous</i> ) from Colombia

Various nematodes, including onchocercids, can infect mustelids and canids. However, there are few records concerning pathogenesis in wildlife species. Diagnosis is made through microscopic observation of blood. Nevertheless, a specific onchocercid assignment is difficult to achieve. In this report, through morphological analysis of microfilariae and molecular characterization using the 18S, 12S, and COI genes, two cases of microfilarial infections were confirmed, Acanthocheilonema sp. infecting tayras (Eira barbara) and Dirofilaria sp. infecting crab-eating fox (Cerdocyon thous). To the authors' knowledge, this is the first report of Acanthocheilonema infection in E. barbara. Cross-sections of adult worms (Acanthocheilonema) were associated with necrotic foci and pyogranulomatous inflammation in the lung parenchyma and pancytopenia, and elevated creatine kinase levels were also observed. Chest x-rays revealed a mixed pulmonary pattern. Meanwhile, Dirofilaria infection in C. thous produced severe generalized suppurative, fibrinous, and hemorrhagic bronchopneumonia and glomerulonephritis, with anemia, neutrophilia, monocytosis, decreased creatinine, and elevated creatine kinase observed. Additionally, findings such as hematuria, proteinuria, glucosuria, amorphous urates, and fine granular casts were observed. Rehabilitation centers provide an opportunity to monitor emerging diseases in wildlife from a One Health perspective. Zoonotic parasites in wildlife should be addressed in an integrated and multidisciplinary manner to develop action plans that incorporate ecological, social, conservation, and public health concerns. This report highlights that Acanthocheilonema sp. and Dirofilaria sp. are potential causes of pulmonary, cutaneous, and renal disease in species like tayras and crab-eating foxes. These species should be considered in management plans for filariasis, which has veterinary and public health implications.