PREVALENCE OF CANINE HEART FILARIA, DIROFILARIA IMMITIS, IN DOGS IN OKINAWA PREFECTURE, JAPAN, 1991-1992

Abstract

From 1991 to 1992, the prevalence of Dirofilaria immitis was clarified in stray dogs from Okinawa, Kume where the first survey was carried out, Miyako, and Ishigaki Isls. of Okinawa Prefecture, Japan. The number of dogs examined was 504 in Okinawa, 13 in Kume, 139 in Miyako and 184 in Ishigaki Isls. In the islands except Miyako Is., about 40% of adult dogs (one year or older) were determined to be infected with D. immitis; but in Miyako Is., 8.3% of adult dogs were positive. All the worms recovered were D. immitis. In Ishigaki Is., the incidence was higher than that reported by Asato et al. (1985). However, in Miyako Is. where young dogs were examined, the incidence was similar to that reported by Asato et al. (1985). In Kume Is., the incidence of D. immitis in house dogs was also examined by the presence of the microfilariae, being 25.5% in outdoor dogs reared outside and none in dogs retained indoor.