Trees Toxic to Horses and Poisonous Plants

Red Maple trees, aka. Acer rubrum, are characterized by their showy fall colors of red, yellow, or vivid orange. All parts of the plant are considered poisonous, but leaves (particularly wilted leaves) are the most deadly. Other toxic trees to horses include, but are not limited to: Silver Maple (Acer saccharinum), Sugar Maple (Acer saccharum), and Horsechestnut trees.

Signs of maple toxicity include a darkening of the mucous membranes, feebleness, loss of appetite, lethargy, ataxia (loss of muscular coordination), stomach discomfort, laminitis, dark urine, and in pregnant mares – spontaneous abortion.


There are common landscape plants that have some poisonous attributes affecting mammals (people, pets, etc.) that may not be as common in our knowledge.  Ingesting any plant or tree leaves, berries, or bark is usually safer to not do – unless absolutely sure it is safe and made for ingestion.  Skin irritations can also occur on plants that we wouldn’t have associated with the likes of poison ivy.  In order to protect the people and pets in your life, be mindful of the following plants in your yard:  Azalea, Black Locust, Buckeye, Daisy, Hellebore, Horse Chestnut, Buckthorn, Clematis, Elderberry, English Ivy, Hydrangea, Oleander, Privet, Rhododendron, Virginia Creeper, Wisteria, and Yew.  Google information about these and any other plants and find out toxicity information.  It is always wise to research before you ingest, let alone plant in your yard if you have curious people and pets that eat things.