PlantFunWater horsetail Toxic?
All parts of the plant are toxic, and alkaloid levels remain stable even after the plant is dried.
Horses are the highest risk group, with toxicity causing vitamin B1 deficiency leading to potentially fatal staggers disease.
Early administration of vitamin B1 is the only curative treatment for affected horses in early disease stages.
FAQ
Is Water horsetail toxic to Humans?
No specific human toxicity data is available; ingestion is not recommended as related Equisetum species cause alkaloid poisoning and thiamine deficiency. (Low)
Is Water horsetail toxic to Cats?
No species-specific toxicity data available; monitor for appetite loss, diarrhea, and neurological abnormalities if ingested. (Low)
Is Water horsetail toxic to Dogs?
No species-specific toxicity data available; monitor for gastrointestinal distress, coordination loss, and lethargy if ingested. (Low)
Is Water horsetail toxic to Horses?
Anorexia, weight loss, restlessness, progressive coordination impairment, saw-horse posture, hindlimb paralysis, blindness, muscle fasciculations, opisthotonus, central seizures, death. (High)
Toxicity Details
No specific human toxicity data is available; ingestion is not recommended as related Equisetum species cause alkaloid poisoning and thiamine deficiency.
No species-specific toxicity data available; monitor for appetite loss, diarrhea, and neurological abnormalities if ingested.
No species-specific toxicity data available; monitor for gastrointestinal distress, coordination loss, and lethargy if ingested.
Anorexia, weight loss, restlessness, progressive coordination impairment, saw-horse posture, hindlimb paralysis, blindness, muscle fasciculations, opisthotonus, central seizures, death.
Toxicity Snapshot
First Aid & Prevention
First 30 Minutes
- • Induce vomiting in conscious, non-seizing animals if ingestion occurred within the past 2 hours.
- • Administer activated charcoal to reduce absorption of toxic alkaloids.
- • Move the affected animal to a quiet, low-light environment to reduce neurological stress.
Contact Vet Immediately
- • If the animal shows signs of coordination loss, paralysis, seizures, or blindness.
- • If ingestion of more than a small amount of the plant is confirmed, especially for horses.
- • If the animal develops persistent diarrhea, appetite loss, or lethargy after exposure.
Prevention
- • Inspect pastures and hay supplies regularly to remove Equisetum species contamination.
- • Restrict access of horses, livestock, and pets to wetland areas where water horsetail grows abundantly.
- • Store animal feed in sealed locations away from areas where this plant may be present.
Treatment & Prognosis
- • Perform decontamination via emesis, activated charcoal, or gastric lavage as clinically indicated.
- • Administer vitamin B1: 100-200 mg orally twice daily on day 1, then once daily for 7-14 days.
- • Provide supportive care for neurological symptoms, diarrhea, and dehydration as required.
Professional Toxicology
• Piperidine alkaloids in the plant inhibit thiamine (vitamin B1) utilization, leading to severe thiamine deficiency.
• Alkaloid content remains stable after drying, so dried plant material in hay is equally toxic as fresh plant.
• Above-ground plant parts have higher average alkaloid concentrations (399 mg/kg dry weight) than below-ground parts.
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.