Plants that are toxic to your horses

As we head into fall and our grasses become less appealing to our horses, many horses will nibble on forages that they would otherwise ignore.  One such plant is the YEW.  There are many varieties of the Yew, all are toxic.  Used as decorative plants around houses and sometimes barns, these bushes are a wreck waiting to happen.

The Yew contains the toxic alkaloid, taxine, which affects the heart and respiratory system.  All parts of the plant are toxic except for the berry.  The leaves are toxic even when dried.  Horses are often poised from ingesting discarded yew cutting found in their pasture or from eating yew-made barn decorations such as wreaths and swags.  Ingestion of even a small amount will result in clinical signs.  Depending of the individual horse, it takes anywhere from a few mouthfuls to 1# of leaves per 1,000# of a horse's body weight to cause death.

Signs of toxicosis:  Sudden death is the most common sign.  Other signs occur within an hour after ingestion and include slowed heart rate, difficulty breathing, trembling, lack of coordination, impaired movement and inability to rise.  Death generally follows 15 to 30 minutes after the onset of signs.

The rapid development of toxic illness make treatment impossible.  Veterinarians may use activated charcoal to decontaminate, if it is early in the progression of the illness.  Other medications are used to treat the specific clinical signs and may be helpful in horses that didn't ingest a lethal dose.  Prognosis is generally poor to fatal.

Most important here is to be aware and deny your horse access to Yew plants.  Better yet, if you have any in your yard...dig them up and burn them!