• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.348-352
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• 2009

This report deals with the morphology of the horsehair worm isolated in canine vomitus. We received a worm in living status. The worm was investigated by using light and scanning electron microscopy (SEM) for species determination. Grossly, the worm was blackish brown in color and 215 mm in length and 1.2 mm in maximum width. Microscopically, the worm was composed of epicuticle, cuticle, epidermis, muscle, mesenchyme, pseudocoel, nerve cord and gut. But the genital organ was not developed. The SEM study revealed that the cuticle contains five types of elevated structures called areoles. The cuticular surface of the parasite is covered by an abundant type of areoles: simple areole, tubercle areole, bulging areole, crowned areole, circumcluster areole. The observed characteristics of the specimen in this study are same to those of genus Chordodes. And we concluded that it is a male of Chordodes koreensis belong to Gordiida. Only nine species of freshwater Nematomorpha are known from Korea, two of which belong to the genus Chordodes. But the case of parasitic horsehair worm in dogs do not recorded, and this is a first gordiosis of dog in Korea.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.586-590
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• 2009

Horsehair worms (Chordodes koreensis) develop as parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. Chordodes koreensis is an accidental parasite of humans, livestock, or pets and poses no public health threat. The male of Chordodes koreensis in the later larval stage from canine vomitus was investigated by the scanning and transmission electron microscopy. In cross sections, the body wall is composed of four components namely epicuticle, cuticle, epidermis, and muscle layers. The parenchymal tissue fills the rest of the body and surrounds the visceral organs such as intestine, and ventral nerve cord but testes were not found. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations called areoles. The cuticle has 17 layers of collagenous fibers spirally wound about the long axis of the worm. The section through the cuticle reveals the layers of large fibers cut obliquely lengthwise, alternating with layers of fibers sectioned obliquely crosswise. The layers of large fiber formed a double helix about longitudinal axis of the worm. The epidermis is a single layer. The muscles were interrupted by the nervous lamella in the only midventral portion. The medulla of muscle plate is composed of lightly stained cytoplasm, mitochondria, weakly developed endoplasmic reticulum, and glycogen granules. Between the medulla of a cell and the plasmalemma lies a broad cortical zone of myofilaments. The circular muscles are absent. The characteristic feature of the cytoplasm is that there was no content in peripheral mesenchyme, but was an abundance of large clear vacuoles which give the cytosome a foamy appearance. The nucleus of mesenchyme is not easily identified in our specimens.