• Parasites, Hosts and Diseases
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• 제56권6호
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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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• 제59권3호
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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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• 제4권4호
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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.

• 융합신호처리학회논문지
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• 제24권1호
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• pp.34-41
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• 2023

최근 인간의 활동 범위가 증가함에 따라 외래종의 유입이 잦아지고 있고 환경에 적응하지 못해 유기된 외래종 중 2020년부터 유해 지정 동물로 지정된 라쿤이 문제가 되고 있다. 라쿤은 국내 토종 너구리와 크기나 생김새가 유사하여 일반적으로 포획하는데 있어서 구분이 필요하다. 이를 해결하기 위해서 이미지 분류에 특화된 CNN 딥러닝 모델인 VGG19, ResNet152V2, InceptionV3, InceptionResNet, NASNet을 사용한다. 학습에 사용할 파라미터는 많은 양의 데이터인 ImageNet으로 미리 학습된 파라미터를 전이 학습하여 이용한다. 너구리와 라쿤 데이터셋에서 동물의 외형적인 특징으로 분류하기 위해서 이미지를 회색조로 변환한 후 밝기를 정규화하였으며, 조정된 데이터셋에 충분한 학습을 위한 데이터를 만들기 위해 좌우 반전, 회전, 확대/축소, 이동을 이용하여 증강 기법을 적용하였다. 증강하지 않은 데이터셋은 FCL을 1층으로, 증강된 데이터셋은 4층으로 구성하여 진행하였다. 여러 가지 증강된 데이터셋의 정확도를 비교한 결과, 증강을 많이 할수록 성능이 증가함을 확인하였다.

• 한국임상수의학회지
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• 제41권3호
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• pp.195-199
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• 2024

A free-range wild raccoon dog (Nyctereutes procyonoides) was rescued with cachexia. Physical examination revealed generalized hyperkeratosis and alopecia typical of scabies as well as hypothermia (35.6℃). The patient was obtunded and severely dehydrated (10%). Hematological parameters included a low packed cell volume (PCV; 15%) and hemoglobin concentration, leukocytosis, and hypoglycemia. A blood smear revealed different subtypes of hypochromic leptocytes, indicating a regenerative response against severe anemia. This case was initially tentatively diagnosed as a severe anemia due to chronic external bleeding presumed to be caused by scabies-induced skin injuries. Darbepoetin alpha (DPO), iron dextran, and fluralaner were administered at the initial presentation, and supportive care including oxygen supplementation, warming, and nutritional support was provided. However, on day 5, the PCV dropped to 5.9% presumably caused by rapid rehydration due to drinking water ad libitum. DPO was boosted on days 5 and 6 along with daily iron dextran. On day 21, the PCV had recovered to 19.8%, and a blood smear evaluation showed a strong regenerative response. This case shows that even if severe anemia occurs in a raccoon dog, it can be managed with an appropriate response. In particular, since the rehydration rate due to food intake is faster than the hematopoietic response rate of raccoon dogs, the PCV may decrease rapidly in the early stage of treatment; therefore, diagnostic examination and additional medical management for hematopoiesis are necessary.

• 한국수의병리학회지
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• 제1권1호
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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.

• 한국수의병리학회지
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• 제1권2호
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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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• 제35권1호
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• pp.1-8
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• 1997

1995년 3월 전북 완주군 소재 모악산에서 포획된 한 마리의 너구리(Nyctereutes procyonoides koreensis)로부터 총 135개체의 참진드기를 채집하여 2속 2종을 동정하였는데, 개피참진드기(Haemaphysalis flava) 117개체와 너구리참진드기(Ixodes tanuki) 18개체를 확인하였다. 그 중 너구리참진드기(신청)는 국내에 서식하는 것으로 처음확인되었다.

• Parasites, Hosts and Diseases
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• 제59권6호
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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.

• 한국환경보건학회지
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• 제18권1호
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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.