Histopathological findings in wild Nutrias (<i>Myocastor coypus</i>) with <i>Capillaria hepatica</i> infection

Abstract

Capillaria hepatica is a zoonotic nematode that uses rodents and other mammals as hosts, especially rats and mice, and causes hepatic granuloma and eventually fibrosis/cirrhosis. However, C. hepatica infection in nutria, a large semiaquatic rodent, has rarely been reported, and histopathologic features of the infection have not been described in detail. We conducted necropsy on 36 wild nutrias. Some animals were found to have milky spots, parasitic eggs and worms within hepatic microgranuloma involving central calcification with cell debris, macrophages, eosinophils and multinucleated giant cells (MGCs). Interestingly, the eggs were closely surrounded by MGCs and appeared to be destroyed without inducing further chronic changes. Based on microscopical examination, C. hepatica infection was diagnosed, and we describe its histopathological characteristics in wild nutrias.

A Case of Fascioliasis in A Wild Nutria, Myocastor coypus, in Republic of Korea

“…Necropsy results showed hepatic milky spots occurring as microgranulomas in 19 nutrias. C. hepatica eggs and worms were detected in 5 of these nutrias which we reported in a previous study [ 1 ]. Unlike the hepatic milky spots induced by C. hepatica , one nutria had a large nodular lesion in the liver.…”

“…As a rodent, nutria is susceptible to many diseases including rabies, equine encephalomyelitis, paratyphoid, salmonellosis, papillomatosis, leptospirosis and toxoplasmosis, rickettsiosis, coccidiosis, and sarcosporidiosis [ 1 ]. Nutria inhabits both terrestrial and aquatic areas and is the reservoir host for various species of parasites.…”

“…It is frequently exposed to parasites, with life cycles in both habitats. They are well known hosts of parasites such as Toxoplasma gondii [ 2 ], Capillaria hepatica [ 1 , 3 ], Giardia spp. [ 3 ], Coccidia [ 2 , 3 ], Echinococcus multilocularis [ 4 ], and Strongyloide myopotami [ 5 ].…”

Development of microsatellite markers and the genetic diversity of <i>Myocastor coypus</i> introduced to South Korea

“…The nutria ( Myocastor coypus ) is a large herbivorous rodent species belonging to Echimyidae [11, 19]. Originally native to subtropical and temperate South America [2, 3], this species was introduced via Bulgaria to South Korea in 1987 primarily for breeding of individuals that could be used for fur and meat industry [3, 9]. This species was accidentally released into the wild, and has become a mammalian species that is frequently found in nature.…”

“…This species was accidentally released into the wild, and has become a mammalian species that is frequently found in nature. The Ministry of Environment in South Korea designated this species as an ecological disturbance species in 2009, and with the local governments, started to control the population in nature [9]. This species is still considered as pests in many areas of South Korea, especially on the southern part, destroying aquatic vegetation, marshes and irrigation systems [9].…”