Prevalence of canine heartworm infection among dogs in Kwangju and Chonnam area

광주와 전남지역 사육견의 개심장사상충(Dirofilaria immitis) 감염률 조사

We have investigated the prevalence of canine heartworm (Dirofilaria immitis) infection among 100 mixed-breed dogs raised in Chonnam Province (Koheung, Posung, Changheung, and Hwasoon) and 100 dogs randomly selected from visiting dogs to the College of Veterinary Medicine, Chonnam National University for routine physical examination. Blood samples taken from dogs were examined for the presence of Dirofilaria immitis microfilaria by the modified Knott's test, and an antigen test which was based on the sandwich ELISA(DiroCHEK(equation omitted), Synbiotics, Inc., San Diego, California, USA) was used to detect the adult heartworm-specific antigen from serum samples. The results were then compared with those of the modified Knott's test. Five(2.5%) of the 200 examined dogs were microfilaria-positive, while 8 dogs(4%) were anti-gen-positive, which suggested that the antigen test was more sensitive than the microfilarial test in detecting heartworm infection. All dogs that were microfilaria-positive were also antigen-positive. The place of origin of the heartworm-positive dogs were of Naju (4/26, 15.4%), Koheung(3/32, 9.4%), and Hwasoon (1/19, 5.3%), while none of dogs raised in Kwangju, Posung, and Changheung areas were infected with the parasite. Although not significant, more infected dogs were observed in older ages, while the difference in infection rate between male (4/98, 4.1%) and female (4/102, 3.9%) was not recognized. Our results indicated that a relatively low infection rate was observed in dogs raised in Kwangju and Chonnam area compared to the infection rate reported previously in other areas of South Korea.