Studies on bovine besnoitiosis in Korea II. A survey on incidence in the enzootic region

The 4,725 cattle in the enzootic region, 6 counties of southern Korea, were surveyed for besnoitiosis epidemiologically by examining the scleral conjunctiva for the cysts and the following results were obtained. The survey showed that 285 cattle, representing 6 per cent of a total of 4,725 cattle examined had S.C. cysts. Only 49 (14 per cent) of them showed clinical sclerodermatitis and the ratio between clinical and inapparent cases was 1:5.8. On age distribution of the S.C. positive cases the highest incidence(10-12 per cent) was seen in amimals that were from 5 to 8 years of age, but clinically apparent cases occurred much more in younger age of animal. In local incidence of S.C. cysts positive cases the prevalence was higher in the secluded districts such as Koheung and Sancheoung counties(9 per cent).