The weather is warming up and it is the time of year when people prefer yard work to house or barn work. Horse owners may not be aware that various yard waste "trimmings" can be toxic to horses and other livestock. In urban areas, neighboring homeowners toss yard vegetative plants over the fence, not realizing these can be deadly when consumed by horses. It is always a good idea to establish a good acquaintance with your neighbors and educate them to the toxic affect yard waste may have on horses and other livestock.
During this time of year, the greatest risk can come from those who need a place to discard their yew bush trimmings. As little as ½ lb. of yew trimmings can be fatal when consumed by a horse. Death can occur within 24 hours, though occasionally death may be precluded by respiratory difficulty, shaking or muscle weakness. Unfortunately, there is no known antidote for yew poisoning.
Other ornamental plants common to our landscape are the Rhododendrons and Azaleas. All parts of these plants, but especially the foliage, contain poison, and two or three leaves may produce a severe toxic reaction. Rhododendrons are more likely to retain green leaves year round than most other plants, and most toxicoses occur in the early spring, when other green forage is unavailable.
Prevention is critical to assure that your horse stays healthy. As summer arrives and new plants begin growing, other plants with the potential to harm horses are also leafing out. For more info on plant toxicity, see the following web sites: