The first case of Capillaria hepatica infection in a nutria (Myocastor coypus) in Korea

Abstract

This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory for necropsy. White-yellowish nodules were found in the liver of 1 of the nutrias at necropsy. Histologically, the lesions were granulomatous, and infiltrations of lipid-laden macrophages, eosinophils, and several multinucleated giant cells were observed. The lesions consisted of numerous eggs and necrotic hepatocytes. The eggs were lemon-shaped and had polar plugs at the ends of both long sides. The eggs were morphologically identified as those of C. hepatica. Worldwide, C. hepatica infection in nutrias is very rare. Nutrias are a kind of livestock, as well as wildlife; therefore, an epidemiological study for parasitic infections needs to be conducted.

Keywords: Capillaria hepatica; liver; nutria.

Fig. 1

Macrophages (red arrowhead) and eosinophils (black arrowhead) infiltrated in the granulomatous lesion. Numerous eggs (black arrow) and necrotic hepatocytes were seen in the lesion. Bar=20 µm.

Fig. 2

Higher magnification of the eggs showing lemon-shaped morphology with polar plugs occurring at the ends of both long sides. Bar=10 µm.

Fig. 3

Longitudinal section of a nematode was found with infiltrations of lipid-laden macrophages in the liver. Bar=50 µm.