新居浜地区に多発した盲目牛について（第2報）

Blind Calves found in Niihama District (The 2nd Report)

緒言

　1969年の早春，新居浜地区に多発した盲目牛の眼所見については，既に同年の中，四国眼科学会で発表し^1），その成因については今後の研究を俟ちたいとした。

　今年も，同一牧場で1月初旬より相次いで盲目牛がホルスタイン種の間に出て，数回の検診を行ない，特にNHK職員と石川哲氏等^2）が現地の調査を行ない，氏等の現地調査では農薬との関係を考えられたようである。

In the early spring of both 1969 and 1970,many calves fed in paddocks became blind show-ing swelling of the knee joints. 44 blind calves were found among 195 animals in 1969 (about 22.5%) and 19 among 200 in 1970 (about 9. 5 %). Among the 63 blind calves, 60 were Hols-tein breed, and the other three were Japanese black and brown breed.

Ophthalmologically, those blind calves showed edema of the optic nerve head associated with hemorrhage on the disk and the retina. In the later stages, the edema subsided, but optic nerve showed well-marked atrophy.

The causes of the disease have not yet been determined.