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Bot Flies, Bee-Like Insect Buzzing around, Laying Eggs on Horse

Code Green - Contact Your Vet to Obtain Useful Advice & Resources

Code Green - Contact Your Vet to Obtain Useful Advice & Resources

    Bot flies are bee-like insects that lay their tiny, pale eggs on the limbs and body of horses in the fall season. They are highly irritating to horses and can even cause herds to stampede.


    Learn to recognize bot flies, eggs and larvae when you see them. They are not thought to cause serious health problems for horses but the adults can be annoying pests. The eggs are ingested by horses and hatch in the stomach, where the larvae attach to the stomach wall during development.

    The most important point is to take bots into account in your horse’s de-worming program. Bot flies will lay their eggs, horses will ingest them over a period of weeks. Consider 1-2 dewormer applications after several hard frosts in the fall to kill the larvae in the stomach. You can remove eggs with a specially shaped bot egg knife.


    Your vet can help you design a de-worming program tailored to your needs and that takes bots into account.

    Author: Doug Thal DVM Dipl. ABVP


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