Additional Common Names:
Scouring rush, Common horsetail, Western horsetail
Found throughout North America and Europe. Prefers moist, cooler areas along ditches, in moist meadows and in disturbed soil areas.
The plant is commonly ingested when horses have very little suitable vegetation to graze on; ingestions over several days or weeks may result in adverse clinical effects. The toxic component breaks down thiamine (an essential nutrient for central nervous system function and metabolism). Clinical signs include weight loss, central nervous system disorders, muscle weakness gradually progressing in severity, convulsions and death.
Toxic to Horses