Head Fly and Maggot Strike Prevention in Sheep

Head fly (Hydrotaea irritans) and the associated risk of blowfly strike around wounds are major welfare concerns in hill sheep, causing painful wound myiasis that requires prevention and prompt treatment.

Key Facts

Head flies target sheep with wounds on their heads, particularly around horns, ears, and eyes
They cause intense irritation that leads to head shaking, rubbing, and tissue trauma
Lucilia sericata and related blowflies lay eggs in moist wounds, and larvae cause tissue destruction (strike)
Strike can progress from eggs to significant tissue destruction within 24 hours in warm conditions
Prevention includes wound care, insecticide application, and removal of head wound risk factors such as fighting

Welfare Considerations

Head fly attack and subsequent blowfly strike around head wounds causes severe, progressive pain and tissue destruction. Sheep with established strike show distress responses including restlessness, foot stamping, and self-trauma as they attempt to relieve the irritation. Without rapid detection and treatment, maggot strike can be fatal. The condition is preventable through regular inspection, prompt wound treatment, separation of fighting animals, and use of licensed preventive products. Hill flocks are at highest risk due to the difficulty of daily observation across extensive terrain.

What You Can Do

Inspect hill sheep for head wounds regularly, particularly during the blowfly season
Apply preventive products promptly to any wounds on the head or around horns
Separate fighting rams or horned animals to prevent the wounds that attract head flies
Seek veterinary treatment immediately for any sheep showing signs of established blowfly strike