Study of apparent hypersensitivity to Culicoides species in sheep in Israel

Between 1983 and 1997, a low incidence of seasonal allergic dermatitis was diagnosed in sheep in Israel aged eight months to eight years, in 10 flocks of a variety of breeds, but not the local Awassi breed. The 40 affected an imals reacted with scratching, biting and vigorous stamping of the feet fro m April to November each year. The principal skin lesions were hyperkeratos is, spongiosis and infiltrations of eosinophils and mononuclear cells, typi cal of an allergic dermatitis which was probably a hypersensitivity reactio n to biting insects. The epidemiological findings in relation to the area o f Israel affected, the breeds of sheep and the distribution of the lesions suggested that the sheep's hypersensitivity was due to the bites of several species of Culicoides.