What Do Blister Beetles Do To Horses?

What can a few tiny blister beetles do to your 1000-pound horse? More damage than you would think. When it comes to blister beetles (Epicauta), even just a few grams of these insects can be lethal to a horse. Blister beetles contain a chemical called cantharidin, which is toxic to cattle, sheep, and especially horses.


Blister Beetles in Alfalfa

As grazing herbivores, all horses inadvertently consume insects from time to time. However, alfalfa poses the highest risk for blister beetles due to the beetles swarming the fields when feeding on the flowers. 

What Blister Beetles Do To Horses? Effects of Consumption

As a result of consumption, affected tissues may range from the mouth, gastrointestinal system, kidneys, and even the heart.

Treatment and Prevention

Experts advise buying hay from the first or late cuttings, and purchasing hay from farmers at what percentage bloom they harvest (under 20% is the safest).

Although there is a no “cure” for cantharidin exposure, there are steps you can take to ensure your horses and livestock are safe from the toxic effects of the blister beetle. If you have concerns over blister beetles, your vet and local agriculture extension office are excellent resources.


Find more detailed information in the link below

Find more articles about horses in