Hypersensitivity to Culicoides midges causing seasonal dermatitis in sheep

Area of Science:

• Veterinary Dermatology
• Allergology
• Insect Vector Research

Background:

• Culicoides midges are significant disease vectors and irritants.
• Insect bite hypersensitivity is well-documented in horses.
• The impact of Culicoides on sheep health is less understood.

Purpose of the Study:

• To confirm ovine hypersensitivity to Culicoides midge bites.
• To investigate seasonal allergic skin disease in Hebridean sheep.
• To assess the prevalence of this hypersensitivity in a susceptible flock.

Main Methods:

• Intradermal allergen testing was employed.
• Hebridean sheep with seasonal allergic skin disease were studied.
• Affected adult sheep were identified within a small flock.

Main Results:

• Ovine hypersensitivity to Culicoides midges was confirmed for the first time.
• 40% of adult sheep in the flock were affected.
• The results suggest a potentially high prevalence of this condition.

Conclusions:

• Seasonal allergic skin disease in sheep can be attributed to Culicoides hypersensitivity.
• The high prevalence indicates significant animal welfare implications.
• Further research into Culicoides-related ovine diseases is warranted.