• Journal of Veterinary Clinics
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• v.37 no.6
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• pp.311-316
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• 2020

Biomarkers used in dogs with heartworm disease include N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI), which are associated with damage to the myocardium. Pulmonary hypertension is one of the clinical signs of canine heartworm disease. The purpose of this study is to investigate the change in the concentration of each biomarker, severity of pulmonary hypertension and the correlation between biomarkers according to the severity of clinical signs. Five healthy dogs and 10 heartworm-infected dogs were recruited for the study. The heartworm-infected group was classified based on the history, clinical signs, and blood assay, thoracic radiography, and echocardiography after confirming the infection according to the results of the commercial ELISA kit (SNAP test, IDEXX Laboratories, Maine, USA). NT-proBNP was higher in the severely infected group than the control group (p < 0.05); cTnI was also higher in the severely infected group than the control group (p < 0.05). The pressure gradient of pulmonary hypertension was higher in the severe group than the mild group (p < 0.05). The severity of pulmonary hypertension was correlated with NT-proBNP (r = 0.818, p < 0.01), cTnI (r = 0.894, p < 0.01). When the correlation of the two serum values for each group was examined, a correlation was not found in the mild group (r = 0.707, p = 0.182), but a correlation was found in the severe group (r = 0.9, p < 0.05). NT-proBNP and cTnI were significantly increased and correlated with severe clinical signs. Pulmonary hypertension was significant higher in the severe group than in the mild group (p < 0.05). Evaluation of blood biomarker concentration and severity of pulmonary hypertension and referring to each correlation between these indicators may be helpful to assess the severity of the heartworm disease.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.225-232
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• 1996

A survey of canine heartworm (nirofilaria inmitis) infections among German shepherds in five areas of South Korea was performed from October 1994 to August 1995 using a microfilarial test (modified Knott's test) and an antigen test (DiroCHEKⓑ Synbiotics, USA). The infection rate of 127 German shepherds (71 males and 56 females) was 10.2% (13/127) by the microfilarial test, but was 28.3% (36/127) by the antigen test, revealing that 24 of the 36 antigen-positive dogs were microfilaria-negative in the peripheral blood . All dogs that were microfilaria-positive were also antigen-positive. Three of the microfilaria-negative and antigen-positive dogs contained 4-15 adult heartworms in the heart and pulmonary arteries upon necropsy. The infection rate among German shepherds was the highest in Hoengsong-gun (Kangwon-do, 84.4%) , while those of Yechon-gun (Kyongsangbuk-do) and Chungwon-gun (Chungchongbuk-do) areas were 20.0% and 14.3%, respectively. None of the dogs in the Kimhae-shi (Kyongsangnam-do) and Kwangiu areas was heartworm positive. The infection rates of heartworm in dogs at the age of 1-3, 4-6. and 7-11 years were 6.3%, 21.4%, and 56.4%, respectively. Based on the fact that the antigen test is more accurate than the microfilarial test, this study strongly indicates that the prevalence rate of canine heartworm in Korea may be higher than previously reported (3.1-23.0%) which utilized microfilarial tests.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.79-83
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• 2001

Dirofilaria immitis parasitizes mainly in the pulmonary arteries and in the heart of dogs and cats. The parasite is also of public health importance, because it often elicits nodules in the pulmonary parenchyma and in the subcutaneous tissues, or sometimes parasitize itself in the eyes of human. In this study, we investigated the prevalence of heartworm infection among 165 dogs on three breeding farms in the vicinity of Seoul, Korea. Of 165 dogs, 83 dogs (50.3%) were infected with the parasite, as revealed by an antigen-detecting test using the peripheral blood. Of these, 23 dogs (20.2%) contained microfilaria using the peripheral blood, which are potential source of transmission to uninfected animals and to humans in the endemic area. None of infected dogs showed any clinical signs associated with the disease. Since the three farms were located in the vicinity of Seoul, the unexpectedly high infection rate could imply that the possibility of exposure of both animals and humans living in the metropolitan Seoul area to the parasite is higher than in the other area of Korea.

• Journal of Veterinary Clinics
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• v.28 no.6
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• pp.595-597
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• 2011

A 5-year-old, intact male Beagle was presented with chronic abdominal pain. The dog was diagnosed with dirofilariasis by positive heartworm antigen detection via ELISA and concurrent microfilaria. Thoracic radiographs revealed cardiomegaly with dilation of the main pulmonary artery. Echocardiography revealed the adult worms in the main pulmonary arteries, but other abnormalities other than heartworm infection were not present. To find the cause of the abdominal pain, exploratory laparoscopy was performed. Ectopic migrating adult heart worms were visualized through exploratory laparoscopy and the clinical sign resolved after removing the heart worm. This report describes removing the ectopic migrating adult heartworms using exploratory laparoscopy in the abdominal cavity.

• Journal of Veterinary Clinics
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• v.34 no.1
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• pp.1-6
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• 2017

Heartworm disease (HWD) in dogs is a life-threatening mosquito-borne disease resulting in right-sided congestive heart failure and inflammatory pulmonary disease. Due to complications from adulticidal therapy with melarsomine, slow kill protocol either with preventive dose of ivermectin or combined with doxycycline has been proposed for an alternative adultcidal therapy in dogs with HWD. Therefore, this study evaluated the clinical outcome of adultcidal therapy in dogs with class II stage of HWD after treating either American Heartworm Society (AHS) or slow kill protocol for 10 months. Clinical outcome after therapy was evaluated by clinical, radiographic and echocardiographic examination along with hematology before (D0) and after therapy (D300). Although clinical signs associated with HWD were all resolved after therapy in both groups, the infection was not cleared out 67% of dogs treated by slow kill protocol at the end of therapy. Furthermore, pulmonary arterial flow of acceleration time to ejection time ratio (AT/ET) and the right pulmonary artery distensibility index (RPADI) have been firstly used for detecting pulmonary hypertension in this study group. The pulmonary hypertension was more common in dogs with mild clinical signs, although tricuspid and pulmonary regurgitation were not detectable in most dogs in this study. Our study findings suggested that the slow kill protocol might not be efficacious enough to clear out HWD in dogs and more attention on the presence of pulmonary hypertension might be necessary for effective management of HWD in dogs.

• Korean Journal of Veterinary Research
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• v.55 no.3
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• pp.205-208
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• 2015

Ten dogs were enrolled in this study: two healthy dogs, two obese dogs without other medical issues and six obese dogs with underlying diseases including pemphigus, chronic active hepatitis, hyperadrenocorticism, narcolepsy, otitis media and heartworm infection. Pyrosequencing of the 16S rRNA gene to explore the gut bacterial diversity revealed that distal gut bacterial communities of samples from patients with pemphigus, otitis media and narcolepsy consisted primarily of Firmicutes, while the major phylum of the distal gut bacterial communities in patients with chronic active hepatitis and hyperadrenocorticism was Fusobacteria. Proteobacteria were the dominant phylum in heartworm infected obese patients.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.233-241
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• 2001

Dirofilaria immitis, the causative agent of canine heartworm disease, inhabits mainly in the pulmonary arteries and the heart of dogs and cats, causing circulatory and respiratory disorders. Although diagnosis of the disease is based on the presence of microfilaria in the peripheral blood or of specific antigens released from the adult worms into the peripheral blood, the severity of the infection and the assessment of disease progression are based on the clinical signs and radiographic image analysis. We analysed 12 mixed-bred Jindo dogs naturally infected with Dirofilaria immitis without any clinical signs and compared the radiographic images of the heart and the lung with the number of adult worms at necropsy. The dorsoventral radiographs of 12 infected dogs revealed that the right caudal lobar pulmonary arteries (RCaLPA) were dialated in 66.7% of dogs, whereas the main pulmonary artery segment was enlarged in 50.3% of dogs. The cranial lobar pulmonary arteries (RCrLPA) were dilated or pruned in 33.3% of dogs. All dogs displayed the interstitial lung pattern, while the vertebral heart size (VHS) was of normal range. Although a range of 9 to 166 adult worms (av. 45.6) was found in the pulmonary arteries, in the heart or in the vena cava, no correlation with the radiographic findings and/or with the clinical signs was observed.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.311-316
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• 2009

The purpose of this meta-analysis was to collect data from the literatures reporting prevalence of canine heartworm (HW) infection in an effort to emphasize the preventive importance of the disease and to serve as baseline data for further studies related to the disease management. Fourteen studies regarding the prevalence of HW infection published during the 1996-2007 were identified using the meta-analytic approach, involving a total of 1,790 cases by microfilarial test and 3,277 cases by enzyme-linked immunosorbent assay (ELISA) antigen test for adult worms. Data analysis was performed separately for pet and military dogs. The overall apparent prevalence of HW infection in pet dogs by microfilarial test and ELISA was 11.7% (183/1,563) and 16.5% (379/2,302), respectively (p < 0.001). No significant difference in prevalence by microfilaria and ELISA was observed between sexes whether assessed by data separately or pooled together. Compared to before 2000, the prevalence by microfilaria after 2000 has increased from 2.5% to 13.1% (p < 0.001), and the rate of adult worm has also increased from 9.9% to 20.3% (p < 0.001). The prevalence determined by ELISA was found to increase with age: 20.7% (n = 1,003) of dogs older than 2 years were positive, compared with 5.0% of dogs (n = 701) under 2 years of age (p < 0.001). Also, outdoor dogs showed significantly higher prevalence than indoor dogs (37.9% versus 3.4%; p < 0.001). For military dogs, the overall prevalence was 38.3% (87/227; 95% CI, 32.1 - 44.7%) by microfilarial test and 38.5% (375/975; 95% CI, 35.4 - 41.6%) by ELISA. This rate was significantly higher than that of pet dogs (p < 0.001). Occult infection rate of 37.5% and 66.7% was found in pet and military dogs, respectively.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.309-313
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• 2005

This study was performed to assess the efficacy of surgical treatment with flexible alligator forceps (FAF) on heartworm infected dogs. Twenty dogs (10 males and 10 females) with heartworm infection, age $5.3\pm3.0\;(mean{\pm}S.D.)$ years and weight $9.3\pm6.5(mean{\pm}S.D.)kg$ were treated with FAF. Adult heartworms were removed by fluoroguided technique with FAF under inhalation anesthesia with isoflurane. For evaluation of the efficacy, removal rate and surgical time were measured, and removal sites were found. Antigen ELISA kit test and autopsy were performed to examine remained adult heartworms. Removal rate of total heartworms was $91.4\%$ including 15 complete retrieval cases and surgical time was $30.0\pm7.6(mean{\pm}S.E.)$ minutes. Heartworms were removed from the right ventricle, main pulmonary artery, and right and left pulmonary artery. Surgical treatment with FAF is an effective method with high removal rate, short surgical time, and various removal sites and it could be considered for the removal of adult heartworms in a dog.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.208-213
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• 2007

A 15 kg 6-year-old intact male Jindo dog with a history of a respiratory distress, hindlimb paralysis with necrosed skin of dorsal digit for three weeks was referred to Animal Medical Center, Chonbuk National University. Heartworm infection was identified by kit examination. In plain thoracic radiographs, dilated pulmonary arteries reverse D sign and focal interstitial pattern was compatible with heartworm infection and possible pulmonary thromboembolism. Abdominal radiographs showed poor serosal detail indicating fluid accumulation within peritoneal cavity. No evidence of musculoskeletal abnormalities was found. Ultrasonography presented focal wedge-shaped hyperechogenecity on the both poles of left kidney, weak or absent pulse on the distal to the external iliac artery as well as ascites and irregular liver margin. Multi-organ failure was strongly supposed by blood profile including leukocytosis, anemia, hemoglobinuria bililubinemia, hypoalbuminemia, imbalance of electrolytes, and increased hepatic and renal function values. Interestingly, the glucose level is remarkably lower in pelvic limb compared to thoracic limb. Suspected pulmonary thromboembolism, renal infarction and femoral arterial embolization causing hindlimb paralysis and dermatic necrosis were confirmed by 3D reconstructed CT imaging. Prior to taking a consideration of euthanasia, interventional radiology was experimentally attempted but failed due to not recovered from general anesthesia. Early and accurate diagnosis of thromboembolism is valuable and 3D reconstructed CT images might be very useful to show the correct way to treat effectively.