• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.130-133
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• 2009

The use of screening tests as part of a diagnostic work-up is common in domestic canine practice, but understanding of the diagnostic test characteristics and factors affecting diagnostic accuracy is not clear among clinicians. This article was aimed to provide clinicians with a better understanding on the selection of test kits and with a proper interpretation of test results using an example from heartworm(Dirofilaria immitis) studies. From the literatures, diagnostic accuracy varied depending on the kits: percent average sensitivity and specificity of ELISA antigen-detecting kits were DiroChek(Synbiotics, USA) 78.1 and 95.2, SNAP(IDEXX, USA) 66.3 and 98.1, and Solo Step(Heska, Switzerland) 69.5 and 97.5, respectively, while the values for three hematological methods(Modified Knott's, direct smear and capillary tube) ranged from 38.4 to 81.8% and from 96.9 to 100%, respectively. Furthermore, it was also reported that the prevalence of heartworm disease in domestic dog populations varied depending on the regions studied: 2.5-22.8% for microfilarial test and 2.2-66.3% by ELISA. The values of predictive values for positive(PPV) and negative(NPV) provide useful information to clinicians on the probability of heartworm infection, but the PPV and NPV are greatly dependent on the heartworm prevalence. This suggests that PPV or NPV values of a test should be interpreted carefully in different clinical settings. Practical methods on the interpretation taking into account heartworm prevalence were discussed.

• 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.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.729-739
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• 2000

Echocardiography, vital signs, microfilaremia, and blood chemistry of 12 Jindo dogs naturally infected with canine heartworms (Dirofilaria immitis) were analysed and compared with those of 5 uninfected control Jindo dogs. Nine of the twelve infected dogs contained microfiaria in the peripheral blood, whereas the presence of adult heartworms in the pulmonary arteries and/or in the heart was detected from four dogs by echocardiography. Among the four echocardiography-positive dogs, two dogs also displayed evidence of heartworms in the right ventricle by echocardiography. Upon necropsy, a total of 547 adult worms was collected from the 12 infected dogs (av = 45.6, range = 9-166). Dogs with positive echocardiograpic images of heartworms contained 48, 74, 104 and 166 adult worms in the heart, pulmonary arteries and/or in the caudal vena cava (av. 98.0), whereas 9 to 39 worms (av. 19.4) were collected from those organs of dogs with negative echocardiography. Most heartworms were found in the right ventricle (438, 80%) at necropsy, whereas relatively fewer worms were found in the pulmonary arteries (96, 17.6%), and in the caudal vena cava (13, 2.4%). The necropsy findings on the location of adult worms significantly differed from the results of echocardiographic analysis in which the right ventricle of most dogs did not show the presence of heartworms. These results indicated that the adult heartworms had been located in the terminal branches of the pulmonary arteries when the host was alive, but the worms moved toward the right ventricle shortly after the heart of the infected dogs stopped beating. Microfilaremia in the peripheral blood was the highest in the blood samples collected at 10 pm. However, the correlation between the number of microfilaria and of adult worms was not observed. Clinical and vital signs of infected dogs did not show any significant difference before and after a 30 minute-exercise at 5 km/hr compared to those of uninfected control dogs.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.334-338
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• 2012

A 3-year-old, intact male Pungsan dog was presented for a 2-week history of a non-weight-bearing lameness of left hindlimb with anorexia. The dog had no history of trauma, and never been routinely vaccinated or treated with heartworm preventatives. The complete blood count showed severe leukocytosis and neutrophilia with left shift. Serum biochemistry showed hypoalbuminemia, azotemia, and increased hepatobilliary enzyme activity. A canine heartworm antigen test was positive. Thoracic radiographs were consistent with heartworm disease as evidences by main pulmonary artery enlargement, right-sided cardiomegaly, and interstitial lung pattern. Echocardiography revealed pulmonary valvular regurgitation and pulmonary hypertension. Selective femoral arterial angiogram was performed, and bilateral femoral arterial occlusion was identified. The dog died after angiogram, and necropsy was performed. At necropsy, adult heartworm and a large blood clot were found within the lumen of left and right femoral artery. This case report describes an unusual migration of heartworm to femoral artery that caused hindlimb lameness.

• 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.

• Korean Journal of Veterinary Research
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• v.49 no.4
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• pp.297-307
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• 2009

Animal shelters are potentially vulnerable to constant exposure to a variety of diseases for both animals and humans, because thousands of animals with unknown histories are being admitted to each shelter on a yearly basis in Korea. The control of disease spread, therefore, can be a major challenge to veterinarians in most shelters. This study investigated the health status of stray dogs admitted to the Gwangju Animal Shelter during the year of 2008, and analyzed types of disorders at the time of admission as well as newly acquired diseases while housed in the shelter. Canine heartworm disease was the most prevalent infection among stray dogs at the time of admission, while the respiratory disorder was the most common shelteracquired disease. The majority of dogs (93.5%) was either small or middle-sized breeds with Maltese (19.7%) and Shih Tzu (16.0%) being the most commonly found stray dogs. Out of 1,143 dogs admitted to the shelter, owners of 128 dogs (11.2%) visited the shelter and found their lost dogs, while 518 dogs (45.3%) were adopted to new families. Results of this study strongly indicate that stray dogs in Korea are exposed to a variety of diseases and the disease control by veterinarians is one of the most important aspects of the shelter management.