Horses and Poisonous Plants

Annemiek has left her thoughts and a question in the "comments" section of yesterday's journal entry. I am reprinting them here with my follow up commentary.

" Hi Lynne, Thanks for your answer, this is all so very fascinating! I am also very interested in what your horses eat. In my study we had a lecture about poisonous plants and the professor on this subject told us domestic horses are not capable anymore to avoid those. I doubt this very much, I’ve read a lot of stories about domestic horses turned lose, which seem to have no problems staying alive without human interference. However, they tell us over and over again that green oak leaves are poisonous for horses as are the green acorns. Our horses eat them both if we don’t prevent them. Maybe you don’t have oak trees at your place, but there must be other “poisonous” trees and plants. How do your horses cope with them I wonder?"

Most traditional texts on equine health (and human health for that matter) are quick to frighten us away from certain plants if they have been found to be problematic when used for food or medicine. Large, bold words like "toxic", "harmful", "noxious" and "poisonous" are very effective in creating an aversion to these powerful plants. This is a good thing, I think, because so many humans are unfamiliar with nature's intelligence and tend to abuse plants in ignorance.

But, as is so often the case, in reality, "toxic" plants are wonderful foods and medicines when they are understood holistically as opposed to reducing them to their isolated constituents.

The many varieties of Oak (Quercus spp.) contain tannic acid (among other compounds) and were used medicinally for its astringent, antibacterial and anti-inflammatory properties. Most of my books tell me that it was the inner bark that was used medicinally, but one text cited use of the leaves and the acorns as well. Native Americans enjoyed acorns as a food and many wild animals find acorns essential to their survival.

There are a few Oak trees growing here at Ravenseyrie, but they are a distinct minority.

We do have a host of other "poisonous" plants in abundance here, probably the most frightful of which is Water Hemlock (Cicuta Maculata). It's alternative name is "Cowbane" due to its dreadful effects when ingested by cattle. All parts of the plant are poisonous. This is the plant that ended the life of Socrates and it takes very little to have its effect.Water Hemlock

I was quite startled to meet the plant for the first time, down on our beach. I had read about it so often and it was quite something to see Water Hemlock in real life. I was surprised how unsettled I felt around it! I gave it a nod of greeting and took a wide berth. The next time I was down at the beach I was horrified to see that several plants had their flowers bitten off. Did the horses eat them? Was it the Whitetail Deer? Black Bear? I have no idea what animal dined on approximately four flowers, but to my great relief neither my dogs nor I came upon any dead carcasses.

Alsike Clover ( Trifolium hybridum) is another plant considered to be quite toxic to herbivores and we have quite a bit of it growing out among the prairie grasses, the Red Clover and other herbs. How do the horses know the difference? I don't know--but they don't seem to eat it, at least not in any quantity that would be harmful. Most likely the plants have an unpalatable element that acts as a natural alarm to the horses, or perhaps an aroma that is off-putting.

Alsike Clover and Water Hemlock are just two "toxic"plants that our horses and mules pass their muzzles over...I could do an entire article on the offerings that grow here side by side with the non-poisonous edibles!

My opinion is that none of these "poisonous" plants are cause for concern when there are plenty of other beneficial and nutrient rich plants for the horses to feast upon. I believe the horses "self-medicate" as needed from the various trees, plants, roots, etc. that are part of their environment. All of us have inherent knowledge about such things...being far less removed from nature than we are, it seems the horses have no difficulties trusting their instinct as it directs them how to make the most of their environment, including what to eat for food and what to nibble upon for medicine.

We have a pretty yellow flowering plant, Tansy (Tanacetum vulgare) which grows in abundance. In addition to its reported toxicity, it has been known to be used as a stomach tonic and an insect repellent. Our horses eat it frequently. They eat the flowers and the leaves and in the autumn and winter they eat the dried stalks!The above photo shows Tansy, growing next to Foxtail Barley Grass--another plant textbooks would prefer to not appear in pastures.

Like Annemiek, I doubt that domestic horses have lost their sense of discernment and I believe they do just fine (in fact better!) in a varied, natural environment, if they have the entire plant buffet to choose from. In Annemiek's case, the Oak leaves and acorns could be problematic if eaten in isolation and not in combination with mixed pasture grass and wild herbs.

At the top of the page as well as at the bottom are two non-toxic plants that grow at Ravenseyrie, Wild Mint and Bunch Berry respectively, aren't they lovely?

Thanks for bringing up this topic, Annemiek! I enjoyed writing about it.