• 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 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.43 no.3
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• pp.517-520
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• 2003

Prevalence of microfilariae, Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema dracunculoides from 506 German Shepherd dogs reared in Korea was investigated by modified Knott's test to detect circulating microfilaria and by acid-phosphatase staining for differentiation of each microfilaria species. In the modified Knott's test, 74 of 506 dogs (14.6%) were microfilaria positive, and the prevelance of each species of microfilaria was 90.5% (67 of 74 samples) for D. immitis, 5.4% (4 of 74 samples) for duplicate infection with D. immitis and D. repens and 4.1% (3 of 74 samples) for mixed infection with D. immitis, D. repens and A. dracunculoides. It was considered that the paying attention to the existence not only D. immitis but also other microfilariae were needed in canine filariasis.

• 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.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.453-455
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• 2013

Heartworm infection is a fatal disease causing heart failure and pulmonary diseases in dogs. This heartworm infection can also occur in wild carnivores including Raccoon dogs. Recent study found that relatively high prevalence rate in wild Raccoon dog population. Therefore, this study was designed to evaluate the prevalence rate of D. immitis in free-roaming Raccoon dogs and the recovery rate of microfilariae in infected Raccoon dogs in Korea. Overall prevalence rate of D. immitis in Korean Raccoon dogs was 17.8%. Prevalence rate in male Raccoon dogs was 21.8%, while that in female Raccoon dogs was 12.8%. Microfilariae were not detected in 17 Raccoon dogs having positive in heartworm antigen test. Our study result suggested that the prevalence rate of D. immitis in Korea is twice higher than that of Japan. In addition, microfilaremia is rare in Raccoon dogs as commonly noticed in cats.

• Parasites, Hosts and Diseases
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• v.52 no.6
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• pp.691-694
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• 2014

The purpose of this study was to conduct a survey of Dirofilaria immitis infection among stray cats in Korea using nested PCR. We included 235 stray cats (121 females and 114 males) and evaluated each for the presence of feline heartworm infection. Blood samples were collected from 135 cats in Daejeon, 50 cats in Seoul, and 50 cats from Gyeonggi-do (Province). Of the 235 DNA samples, 14 (6.0%) were positive for D. immitis. The prevalence of infection in male cats (8/114, 7.0%) tended to be higher than that in female cats (6/121, 5.0%), but the difference was not statistically significant. In each location, 8, 2, and 4 cats were positive for infection, respectively, based on DNA testing. No significant differences in the prevalence were observed among the geographic regions, although the rate of infection was higher in Gyeonggi-do (8.0%) than Daejeon (5.9%) and Seoul (4.0%). We submitted 7 of the 14 D. immitis DNA-positive samples for sequencing analysis. All samples corresponded to partial D. immitis cytochrome c oxidase subunit I gene sequences with 99% homology to the D. immitis sequence deposited in GenBank (accession no. FN391553). To the best of our knowledge, this is the first survey using nested PCR to analyze the prevalence of D. immitis in stray cats in Korea.

• Korean Journal of Veterinary Service
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• v.37 no.3
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• pp.197-202
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• 2014

Dirofilaria immitis infection is one of the most important parasitic diseases in dogs and public health. It often elicits nodules in the pulmonary parenchyma and in the subcutaneous tissues of human. In this study, we investigated the prevalence of D. immitis infection among 754 dogs in Seoul area from April to December 2012. The infection rate of 754 dogs was 9.8% (74/754) by the antigen test (canine SNAP 4Dx). The infection rates of D. immitis in dogs at the age of < 2, 2~4, 5~7, 8~10, and > 10 years were 3.7% (7/189), 12.9% (30/233), 15.0% (19/127), 9.8% (18/184), and 0% (0/21), respectively. The infection rates in the female and male dogs were 9.7% (33/340) and 9.9% (41/414), respectively. The regional infection rates in northern and southern Han river region of Seoul were 10.7% (44/410) and 8.7% (30/344), respectively. In order to confirm D. immitis infection, we performed PCR on serum samples of 74 dogs which tested positive for D. immitis antigen by the antigen test and we detected a specific gene ITS-2 in 59 serum samples. In conclusion, this study suggests that treatment and preventive care on the D. immitis infection should be considered in dogs of Seoul area.

• 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.

• Korean Journal of Veterinary Service
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• v.41 no.3
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• pp.179-183
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• 2018

A survey on the seroprevalence of Dirofilaria immitis infection among 2,197 Jindo dogs (371 males, 1,826 females) was conducted from 2011 to 2015 using an antigen test (SNAP 4Dx plus, IDEXX, USA). The overall seroprevalence of D. immitis infection in Jindo dogs was 21.8% (479/2,197), and an increase was observed in the seroprevalence of infection from 19.4% in 2011 to 25.8% in 2015. The infection rates were higher among male dogs (32.1%, 119/371) than female dogs (19.7%, 360/1,826)(P<0.01). The infection rates of D. immitis in Jindo dogs at the age of under 1 years-old, 1 to 2 years-old, 2 to 3 years-old and over 3 years old were 10.7% (76/710), 20.0% (190/950), 36.4% (156/428) and 52.3% (57/109), respectively. The older dogs had higher infection rates than the younger dogs (P<0.01). This study indicates that the prevalence rate of D. immitis in Jindo dogs is higher than previously reported in studies which utilized an antigen test.