A small creature is causing major issues for some Midwest horses.

KSFY reports that toxic beetles are to blame for the deaths and illnesses of horses on a Wisconsin ranch. Red Ridge Riding Stable in Mauston, Wisconsin had some flooding this past summer that caused their hay to be unusable. To resolve the issue, the owners of the stable bought hay and alfalfa from farms in South Dakota and Wyoming. This hay is speculated to have been tainted by blister beetles. According to the report, blister beetles release a toxin when crushed during harvest. Veterinarian Dave Kolb told the Wisconsin State Journal that "the toxin irritates the linings of horses' stomachs and intestines".

Orkin states that "blister beetles are soft-bodied beetles that range in size from 1 to 2.5 cm in length, and range in color from ash gray to bright yellow with black stripes. The beetles can pose as a serious health threat to horses or sheep when large numbers of them and toxic amounts of canthardin are ingested in hay or other plants that are used for livestock feed."

The beetle-contaminated hay is seemingly responsible for the deaths of 14 horses and for sickening another 100 horses on the ranch. There have been no other reports of horse deaths from tainted hay.