Poisonous Plant Quiz

Field HorsetailSorry! That's the wrong answer. This is Field Horsetail. It is found in poorly drained soils, as well as low, sandy or gravel soils with good drainage. It can severely suppress field crops and other plants. It is especially poisonous in young horses. Hay containing this weed may be more poisonous than fresh plants in the field. Symptoms are slow to develop.


  • jaundice
  • loss of appetitie
  • weakness
  • staggering gait
  • excitability
  • paralysis

There is no known anti-dote. Toxic substance is thiaminase plus an unknown factor which wipes out Vitamin B.

A veterinarian should be consulted immediately for supportive treatment to reduce the damage caused by ingestion of poisonous plants.

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For more information:
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E-mail: ag.info.omafra@ontario.ca

Author: Penny Lawlis - Animal Care Specialist/OMAFRA
Creation Date: Not Available
Last Reviewed: November 2003