Hypersensitivity to Culicoides midges causing seasonal dermatitis in sheep.

Culicoides midges are important as vectors of disease, as an irritant with severe effects on human outdoor activities in certain areas and as the cause of insect bite hypersensitivity in domestic animals (most notably horses). Here we report, for the first time, the confirmation of ovine hypersensitivity to Culicoides midges in Hebridean sheep suffering from seasonal allergic skin disease using intradermal allergen testing. The affected sheep formed 40% of the adults in the small flock, and this indication of a potentially high prevalence of a condition with welfare implications is of concern.