PlantFunGreat horsetail Toxic?
All plant parts are toxic, with alkaloid content remaining stable after drying so dried material is equally dangerous.
Ingestion causes thiamine (vitamin B1) deficiency, leading to neurological damage and potentially fatal outcomes, especially in horses.
Vitamin B1 administration is only curative if given in the early stages of poisoning.
FAQ
Is Great horsetail toxic to Humans?
No confirmed human poisoning cases recorded; ingestion may cause gastrointestinal distress, neurological impairment and thiamine deficiency based on livestock data. (Low)
Is Great horsetail toxic to Cats?
No specific cat toxicity data available; risk is considered low but ingestion may cause mild gastrointestinal or neurological signs. (Low)
Is Great horsetail toxic to Dogs?
No specific dog toxicity data available; risk is considered low but ingestion may cause mild gastrointestinal or neurological signs. (Low)
Is Great horsetail toxic to Horses?
Loss of appetite, weight loss, reduced milk production, diarrhea, neurological symptoms, 'staggers disease' from thiamine deficiency, incoordination, saw-horse stance, hindlimb paralysis, recumbency, blindness, muscle fasciculations, opisthotonus, central seizures, death. (High)
Toxicity Details
No confirmed human poisoning cases recorded; ingestion may cause gastrointestinal distress, neurological impairment and thiamine deficiency based on livestock data.
No specific cat toxicity data available; risk is considered low but ingestion may cause mild gastrointestinal or neurological signs.
No specific dog toxicity data available; risk is considered low but ingestion may cause mild gastrointestinal or neurological signs.
Loss of appetite, weight loss, reduced milk production, diarrhea, neurological symptoms, 'staggers disease' from thiamine deficiency, incoordination, saw-horse stance, hindlimb paralysis, recumbency, blindness, muscle fasciculations, opisthotonus, central seizures, death.
Toxicity Snapshot
First Aid & Prevention
First 30 Minutes
- • Immediately remove all access to the plant to prevent further ingestion.
- • Induce vomiting in conscious animals that ingested the plant within the last 2 hours.
- • Administer activated charcoal to bind unabsorbed toxins in the gastrointestinal tract.
Contact Vet Immediately
- • Any confirmed or suspected ingestion of the plant by horses or other livestock.
- • Observation of neurological symptoms including incoordination, paralysis, blindness or seizures.
- • Presence of unexplained loss of appetite, weight loss or diarrhea in animals with access to the plant.
Prevention
- • Inspect all hay and livestock feed for contamination with horsetail plant material.
- • Remove all horsetail plants from grazing pastures and areas accessible to pets and livestock.
- • Avoid feeding forage containing any horsetail species to livestock or companion animals.
Treatment & Prognosis
- • Perform decontamination procedures including gastric lavage and activated charcoal administration as clinically indicated.
- • Administer vitamin B1 (thiamine) orally at 100-200mg twice daily on day 1, then once daily for 7-14 days as prescribed.
- • Provide symptomatic supportive care including fluid therapy for diarrhea and seizure control for neurological symptoms as needed.
Professional Toxicology
• Piperidine alkaloids in the plant inhibit thiamine (vitamin B1) activity, leading to thiamine deficiency and associated neurological damage.
• Total alkaloid content remains stable when the plant is dried, so dried plant material is as toxic as fresh material.
• Above-ground plant parts contain higher average alkaloid content (399 mg/kg dry weight) than below-ground parts (261 mg/kg dry weight), with levels peaking in summer and late growth stages.
Information from CliniTox veterinary text.
The following plants look similar and may be confused:
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Data Sources
This information is for reference only and does not constitute medical advice. If ingestion or poisoning is suspected, seek medical or veterinary attention immediately.