Plants Toxic to Horses

Buttercup Species

Tall Buttercup. Photo Credit: Montana Statewide Noxious Weed Awareness and Education Program, Montana State University, Bugwood.org

• All livestock are affected.
• Toxicity - low
• Common in pastures and marshes
• Poisonous part - leaves and flowers
• Symptoms - irritated tissues in the mouth and throat. Affects the gastrointestinal system (colic, diarrhea), causes excessive salivation.

Pokeweed

• Affects all livestock - especially pigs.
• Toxicity – moderate
• Found in rich, disturbed soils such as barnyards, moist woodlands and pastures
• Poisonous part - all parts, but mainly the roots
• Symptoms - Affects the gastrointestinal system (colic and diarrhea) and central nervous system (convulsions).
• Cooked berries are sometimes used in pies.

Nightshade Species

• All livestock are affected.
• Toxicity - moderate
• Found in disturbed soils, rich pastures, and woods
• Poisonous part - berries and vegetation
• Symptoms - Affects central nervous system (trembling, paralysis, shock, coma); gastrointestinal system (colic, diarrhea and impaction)

Horsenettle

• All livestock are affected.
• Toxicity - moderate
• Distribution - pastures, cultivated fields, hay fields
• Poisonous part - all parts, especially berries. Remains toxic in hay.
• Symptoms - Affects the gastrointestinal (salivation, colic, diarrhea) and central nervous system (muscle tremors, weakness, depression)

Poison Hemlock

• All livestock are affected.
• Toxicity - extremely toxic, 4-5 pounds will kill a 1,000 pound animal
• Distribution - disturbed or waste areas, roadsides, ditches
• Poisonous part - all parts are extremely toxic
• Symptoms - Affects the central nervous system (blocked spinal cord reflexes, muscle tremors, incoordination, paralysis), frequent urination, sudden death due to respiratory failure.