Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Larkspur, Monkshood Toxicity

Synonyms: Misc. Plants Containing Toxic Alkaloids


There are many species of plants that contain toxic alkaloids, poisons that cause a variety of severe clinical signs and sudden death in horses. Monkshood is more toxic to horses than Larkspur.

Sign of toxicity from these plants are hard to differentiate from other acute diseases, and include cardiac arrhythmias, weakness, salivation, high heart and respiratory rates, poor blood pressure and collapse.

Diagnosis requires evidence of consumption of the plant, along with compatible signs of disease.

There is no known treatment for these toxins in horses. Eliminating exposure to the plants immediately is critical. Trying to reduce absorption by using activated charcoal may be helpful. Unfortunately, this opportunity is rare.

It is always important to minimize stress during treatment, as this worsens the signs.

my vet's role


The prognosis is guarded to poor for horses showing signs after ingesting these plants.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
more observations

Questions To Ask Your Vet:
  • How can I manage my horses & pastures to reduce the likelihood of these toxicities?

Know the plants that grow in your pastures, and inspect your pastures regularly. Research the plants that grow in and around all of the areas that your horses live. Avoid planting toxic plants when landscaping around your barn. When in doubt, take a picture of the plant and send it to your vet or county extension agent for discussion. Be particularly careful when packing and camping with your horses.

Author: Doug Thal DVM Dipl. ABVP