• Parasites, Hosts and Diseases
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• v.56 no.6
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• pp.567-575
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• 2018

Present study was performed to describe the morphological and molecular characterization of Toxocara tanuki (Nematoda: Ascaridae) from Korean raccoon dog, Nyctereutes procyonoides koreensis, naturally infected in the Republic of Korea (Korea). Juvenile and adult worms of T. tanuki were recovered in 5 out of 10 raccoon dogs examined and the larval worms were detected in 15 out of 20 muscle samples (75%). Small lateral alae were observed on the cranial end of the body in male and female adults and 2 long spicules (3.0-3.5 mm) were characteristically observed in the posterior end of males. In SEM observation, 18 pairs of proximal precloacal, a precloacal median, a postcloacal median and 5 pairs of postcloacal papillae were uniquely revealed in the posterior portion of males, but the proximal papillae were not shown in the lateral ends of females. Molecular analysis on the 18S rRNA partial DNA sequences was revealed the same finding in both samples, adult worms and muscle larvae, which are closely related to T. tanuki. In conclusion, it was confirmed for the first time that T. tanuki is indigenously distributed, the Korean raccoon dog is acted as the natural definitive host of this nematode in Korea and the morphological characteristics of T. tanuki were shown in specific structure for single postcloacal median papilla in male.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.303-309
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• 2021

In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807-1,103 ㎛ long and 1,270-1,550 ㎛ wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33-35×15-16 ㎛ in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.159-176
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• 2023

The conservation of the raccoon dog (Nyctereutes procyonoides) in South Korea requires the protection and preservation of natural habitats while additionally ensuring coexistence with human activities. Applying habitat map modeling techniques provides information regarding the distributional patterns of raccoon dogs and assists in the development of future conservation strategies. The purpose of this study is to generate potential habitat distribution maps for the raccoon dog in South Korea using geospatial technology-based models. These models include the frequency ratio (FR) as a bivariate statistical approach, the group method of data handling (GMDH) as a machine learning algorithm, and convolutional neural network (CNN) and long short-term memory (LSTM) as deep learning algorithms. Moreover, the imperialist competitive algorithm (ICA) is used to fine-tune the hyperparameters of the machine learning and deep learning models. Moreover, there are 14 habitat characteristics used for developing the models: elevation, slope, valley depth, topographic wetness index, terrain roughness index, slope height, surface area, slope length and steepness factor (LS factor), normalized difference vegetation index, normalized difference water index, distance to drainage, distance to roads, drainage density, and morphometric features. The accuracy of prediction is evaluated using the area under the receiver operating characteristic curve. The results indicate comparable performances of all models. However, the CNN demonstrates superior capacity for prediction, achieving accuracies of 76.3% and 75.7% for the training and validation processes, respectively. The maps of potential habitat distribution are generated for five different levels of potentiality: very low, low, moderate, high, and very high.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.1
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• pp.34-41
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• 2023

In recent years, as the range of human activities has increased, the introduction of alien species has become frequent. Among them, raccoons have been designated as harmful animals since 2020. Raccoons are similar in size and shape to raccoon dogs, so they generally need to be distinguished in capturing them. To solve this problem, we use VGG19, ResNet152V2, InceptionV3, InceptionResNet and NASNet, which are CNN deep learning models specialized for image classification. The parameters to be used for learning are pre-trained with a large amount of data, ImageNet. In order to classify the raccoon and raccoon dog datasets as outward features of animals, the image was converted to grayscale and brightness was normalized. Augmentation methods were applied using left and right inversion, rotation, scaling, and shift to create sufficient data for transfer learning. The FCL consists of 1 layer for the non-augmented dataset while 4 layers for the augmented dataset. Comparing the accuracy of various augmented datasets, the performance increased as more augmentation methods were applied.

• Korean Journal of Veterinary Pathology
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• v.1 no.1
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• pp.77-79
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• 1997

Capillaria hepatica a primary trichuroid nematode parasite in rodents, has been reported in wide range of secondary hosts including humans. We report a rare case of Capillariasis in a 4-year old raccoon dog(Nyctereutes procyonoides) submitted to the Veterinary Diagnostic Laboratory Chonbuk National University for necropsy on July 5, 1996. Grossly the thoracic cavity contained approximately 200 mls of blood-tinged exudate. Edematous lesion was present around aorta and vena cava. liver was slightly swollen and mottled and contained multifocal yellowish-white lesions ranging from 1 to 3 mm in diameter. Histologically liver lesions were localized around central veins and were characterized by cell swelling and necrosis with mixed inflammatory cells surrounding parasite eggs. These eggs were barrel-shaped with polar caps consistent with Capillaria hepatica.

• Korean Journal of Veterinary Pathology
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• v.1 no.2
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• pp.153-156
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• 1997

This is the first recorded case of Sarcoptes scabiei in a Korean female raccoon confirmed by light and scanning electron microscopies. Grossly the skin on the abdomen head and legs was markedly thickened with alopecia and encrustation. histopathologically skin showed epidermal hyperplasia with spongiotic degeneration and parakeratosis. Ectoparasites were present in superficial and deep epidermal layers. Small numbers of leukocytes predominantly neutrophils were associated with the parasitic infestation. Scanning electron microscopy examination of affected skin scraping demonstrated round to oval parasitic mites measuring approximately 180 -250 x 220 - 350 um in size. The mites possessed four pairs of legs of which the two anterior pairs appeared relatively long with unjointed stalks while the two posterior leg pairs were rudimentary. these morphological features were consistent with Sarcoptes scabiei.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.1-8
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• 1997

A total of 135 hard ticks consisting of 2 species of 2 genera, 117 Hasmcphvsnlis filava and 18 Ixones tcnuki, were collected from a Korean raccoon dog (Nwctereutes procvonoines koreenis) caught at the Moaksan (Mt.), Chollabuk-do, Korea in March 1995. It is the first record that I. tnnuki appears in the Korean fauna.

• Parasites, Hosts and Diseases
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• v.59 no.6
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• pp.645-649
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• 2021

Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular characteristics, the flukes were identified to Cryptocotyle lata. The adult C. lata were minute, transparent, pentagonal, 522 ㎛ long by 425 ㎛ wide. Ceca extended into post-testicular region. Ventrogenital sac elliptical, 79 ㎛ by 87 ㎛ with genital pore and ventral sucker. Two testes semielliptical and slightly lobed, located in the posterior region, right testis 173 ㎛ by 155 ㎛, left testis 130 ㎛ by 134 ㎛. In a phylogenetic tree, the fluke specimen of this study was grouped with C. lata divergent from Cryptocotyle lingua. We report here N. procyonoides koreensis first as a natural definitive host of C. lata.

• Journal of Environmental Health Sciences
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• v.18 no.1
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• pp.112-115
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• 1992

1989년 10월부터 뉴저지주에서 야생동물 광견병이 유행되기 시작하였다. 광견병이 의심되는 야생동물 및 가축을 광견병 항체항원 반응으로 검사하여 1990년 1월부터 1990년 12월까지 유행 진행 상황을 점검하였다. 그 결과를 요약하면 다음과 같다. 1. 야생동물 광견병 유행이 1년에37mile 정도로 전파되었다. 2. 광견병으로 판명된 야생동물 중 Raccoon이 87%로 제일 많았고, Skunk가 6.4%였다. 3. 동물별 광견병 양성률은 Raccoon이 28.8%로 제일 높고 Skunk가 20.8%로 그 다음이었다. 4. 계절별 광견병 양성률은 1월에 11.4% 2월에 6.9% 9월에 21.0% 12월에 31.0%였다.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.361-365
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• 2022

We report a species of diplostomid fluke recovered from 3 carcasses of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 107 diplostomid flukes were recovered from the small intestines of Korean raccoon dogs, which were obtained from the Gangwon Wildlife Medical Rescue Center. Worms fixed with 10% neutral formalin were subjected to microscopic observation and those fixed in 70% ethanol were used for molecular genomic analysis. The worm was divided into 2 separate parts, forebody and hindbody, with a total length of 3,020-4,090 (3,855) ㎛ and a width of 1,210-1,770 (1,562) ㎛. The boat-shaped forebody has a pair of characteristic tentacular appendage, 2 suckers, holdfast organ, and vitelline follicles. The oval to cylindrical hindbody has reproductive organs. The ovary was round or elliptical and located in the anterior of the testes. Two large testes were slightly segmented and tandemly arranged, occupying almost half of hindbody. The short uterus contained a relatively small number of unembryonated eggs sized 130-140×85-96 ㎛. The partial sequence of 18S rRNA of this fluke was consistent with Alaria alata. Based on the morphological and molecular characteristics, the diplostomid flukes recovered from the small intestine of Korean raccoon dogs were identified as A. alata (Digenea: Diplostomidae).