• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.177-181
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• 1999

This study was undertaken to clarify the more accurate detecting method of Dirofilaria immitis. Seven dogs, average 7.47 years old, confirmed with Dirofilaria immitis infection by modified Knott's method were used as the experimental animals. cDNA was constructed using oligodT(15) primer after extracting total RNA from the blood of dogs that were confirmed with Dirofilaria immitis infection. As a result of polymerase chain reaction with template using constructed cDNA, the predicted products of a 378 base-pair DNA fragment was amplified. From these results, RT-PCR was more sensitive and effective than modified Knott's method to detect Dirofilaria immitis in dogs.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.545-550
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• 2002

The raccoon dog (Nyctereutes procyonoides) may be infected by Dirofilaria immitis. However, there has been no report on dirofilarial infection in the raccoon dog in Korea. In this study, we report on D. immitis infection in two wild raccoon dogs captured in the Daejeon area. The two raccoon dogs were referred to the Veterinary Teaching Hospital, Chungnam National University for diagnosis of D. immitis infection. The modified Knott's test for the detection of blood D. immitis microfilariae was positive, and serological test (FASTest$^{(R)}$ HW Antigen ELISA kit, Diagnostik Mega Cor, Austria) for D. immitis was positive as well. Additionally, D. immitis microfilariae were differentiated from other microfilariae by using acid phrnphatase histochemical staining (Leucognost-SP$^{(R)}$kit, Diagncstica MERCK, Germany). The two raccoon dogs were necropsed and D. immitis infection was confirmed.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.1-6
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• 2020

Unlike previous studies that reported the infection rates of Dirofilaria immitis in companion dogs, D. immitis genes were tested directly on mosquitoes to see how many mosquitoes actually carry larvae. Mosquito samples were collected from six parks in Incheon from March to August 2018. A total of 18,589 mosquitoes was collected, classified by type and then made 575 sample pools based on 50 mosquitoes. The PCR method was used to detect Dirofilaria immitis genes of sample pools. Dirofilaria immitis genes were detected in 7 of the 575 pools, and these positive mosquito samples were collected in 4 out of the 6 parks. The types of detected mosquitoes were Aedes dorsalis and Ochlerotatus koreanus which have been identified to act as a vector for heart worm propagation in Incheon. Based on these results, it was concluded that D. immitis genes were found in mosquitoes in the neighborhood park.

• Korean Journal of Veterinary Research
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• v.52 no.1
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• pp.53-56
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• 2012

Dirofilaria (D.) immitis is an important canine parasitic nematode in dogs. D. immitis parasitizes the right ventricle and pulmonary artery of dogs. An ivermectin and pyrantel pamoate compound (IPPC) was administered to dogs naturally infected with this parasite. IPPC is composed of 68.0, 136.0 and $272.0{\mu}g$ of ivermectin and 57.0, 114.0 and 227.0 mg pyrantel pamoate for small, middle, and large animals. Ivermectin has activity against nematodes and ectoparasites in dogs. Pyrantel pamoate is also effective against nematodes in dogs. Our results showed that this drug combination has good efficacy in D. immitis infected dogs.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.375-377
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• 2013

In the present study, we first report the seroprevalence of Dirofilaria immitis in dogs in Shenyang, northeastern China. Sera from 528 randomly selected dogs were examined for D. immitis antigen using SNAP$^{(R)}$4Dx test kit; 12.7% tested showed seropositive. No significant difference of infection was observed in different genders and breeds (P>0.05), but the difference was significant in different age groups and rearing conditions (P<0.05). The result suggested that the risk of exposure to D. immitis in dogs is high in Shenyang, and should be given attention.

• Parasites, Hosts and Diseases
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• v.43 no.2 s.134
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• pp.65-67
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• 2005

The intestines and hearts of dogs were examined for Toxocara canis, Toxascaris leonina, and Dirofilaria immitis, after necropsy between June 26 and September 29, 2004 in Chuncheon, Korea. Of the 662 dogs examined, 6 were infected with T. canis $(0.9\%),\;86\;with\;T.\;leonina\;(13.0\%)$. Fifty dogs were infected with D. immitis among 500 dogs examined $(10.0\%)$. Five were co-infected with T. canis and T. leonina, and three were co-infected with T. leonina and D. immitis. The cumulative positive infection rate for three species was $134/662(20.2\%)$. Considering previously reported seropositive rates of T. canis excretory-secretory antigen, i.e., $5\%$ in the adult population in Korea, the possibility of toxocariasis caused by T. leonina should be reevaluated.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.385-389
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• 2009

This study was attempted to survey on the prevalence of canine heartworm infection (Dirofilaria immitis) in the Incheon area in 2006. This study showed comparative infection rates of canine heartworm in conjunction with different geographic locations and rearing environments (i.e., indoor, outdoor or free roaming). In total, 24 dogs (6.0%) were D. immitis positive among a total of 400 tested dogs. The geographic distribution of detection rates was Nam-gu (2 dogs, 6.7%), Yeonsu-gu (1 dog, 3.0%), Namdonggu (5 dogs, 8.0%), Pupyoung-gu (4 dogs, 6.7%), Kanghwa-gun (8 dogs, 13.0%), and Onjin-gun (4 dogs, 11.1%). In addition, 4 dogs (2.0%) or 20 dogs (10.0%) were positive for D. immitis among 202 indoor dogs or 198 outdoor dogs including free roaming dogs, respectively, while 13 dogs (11.7%) were positive for D. immitis among 111 outdoor dogs excluding free roaming dogs. In the case of 87 free roaming dogs, 7 dogs (8.1%) among them were positive for D. immitis.

• Parasites, Hosts and Diseases
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• v.40 no.4
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• pp.195-198
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• 2002

This study was performed to investigate whethere there is cross-reactivity between Dirofilaria immitis and three intestinal nematodes of dogs. In ELISA, D. immitis- infected dog sera obtained at the 4th molting stage (9-11 weeks) and microfilaremic stage (25-30 weeks) were shown to be highly reactive with crude extract of T. canis. In immunoblotting, some antigenic fractions, 44, 57 88, 100 kDa of crude extract of T. canis, were found to be positive reaction with sera of dogs infected with D. immitis. However, little or no cross-reaction were observed between sera of D. immitis-infected dogs and crude extract antigen of T. vulpis or A. caninum. These result suggest that there are partial cross reaction between sera of D. immitis-infected dogs and the antigen of T. canis.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.64-70
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• 2019

Dirofilaria immitis (D. immitis) is a filarial nematode that causes cardiopulmonary dirofilariasis in dogs. In the late stages of infection, infected dogs show one or more symptoms and advanced heart disorder with perivascular inflammation. To detect D. immitis specifically and efficiently in the early stages of infection, a duplex TaqMan qPCR assay was developed based on previous studies using primers and probes specialized to detect D. immitis cytochrome c oxidase subunit I (COI) and dog glyceraldehyde-3-phosphate dehydrogenase (GAPDH). As positive controls, plasmid DNAs were constructed from D. immitis COI or dog GAPDH and a TA-cloning vector. Simplex and duplex TaqMan qPCR assays were performed using the specific primers, probes, and genomic or plasmid DNA. The duplex reaction developed could detect D. immitis COI and dog GAPDH in the same sample simultaneously after optimization of the primer concentrations. The limit of detection was 25 copies for the simplex and duplex assays, and both showed good linearity, high sensitivity, and excellent PCR efficiency. The duplex assays for pathogen detection reduce the costs, labor, and time compared to simplex reactions. Therefore, the duplex TaqMan qPCR assay developed herein will allow efficient D. immitis detection and quantification from a large number of samples simultaneously.

• Korean Journal of Veterinary Research
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• v.54 no.1
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• pp.53-54
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• 2014

This study was conducted to determine the serum cardiac troponin I (cTnI) concentrations in clinically normal (uninfected) Korean Jindo dogs and those infected with Dirofilaria (D.) immitis. Forty Korean Jindo dogs (22 females, 18 males) were obtained from two kennels in the Boryeong area of Chungnam Province and the Daejeon area, Korea. Significantly higher cTnI concentrations were observed in D. immitis-infected dogs than clinically normal dogs. cTnI testing in addition to thoracic radiography, echocardiography, and electrocardiography shows promise as an additional method for diagnosis of heartworm infection.