Fly Strike Welfare in Horses in Summer

Flies cause significant welfare harm to horses through harassment, biting, and myiasis (fly strike). Fly control is an essential component of summer horse welfare management.

Key Facts

Horse flies, stable flies, and horn flies all cause painful bites affecting horse behaviour
Fly harassment causes horses to crowd together, stamp, and rub causing self-trauma
Warble fly larvae can infest horses causing painful subcutaneous lesions
Repellents, fly sheets, masks, and stable management reduce fly load significantly
Botfly larvae in the stomach, while rarely causing clinical disease, represent welfare concern

Welfare Considerations

Fly harassment causes significant welfare compromise during summer months. The constant irritation of biting flies causes horses to spend considerable energy and time on defensive behaviours rather than grazing and resting. Horses in high fly areas show elevated cortisol and reduced grazing time. Effective fly control combining physical barriers including fly rugs and masks, chemical repellents, and stable management that removes manure rapidly and uses fly predator wasps where feasible provides meaningful welfare improvement during peak fly season.

What You Can Do

Fit appropriate fly rugs and masks to horses during peak summer fly season
Remove manure from paddocks and stables regularly to reduce fly breeding
Use insect repellents on exposed skin areas not covered by rugs
Consider fly predator wasp programmes to biologically reduce stable fly populations