As you finish up your fall yard work, be mindful of foliage that can be toxic to horses. Red maple leaves, in particular, contain toxins that bind to hemoglobin, the protein in red blood cells that normally carry oxygen throughout your horse’s body. This destroys the cells, leading to organ failure within 48 to 72 hours. Green leaves that fall and wilt—when a branch falls during a summer storm, for instance— are most toxic, but those that wilt naturally in autumn are also a danger. Ingesting only a few handfuls can be deadly for a horse.

If you have red maple trees on your property and anticipate a large “dump” of leaves, the safest solution is to relocate your horses to another area until you can gather and dispose of the foliage. If there’s only a slight chance of red maple leaves blowing in, trying to identify and remove them from fields may be impossible. Instead, make sure your horse has plenty of hay. Most won’t graze on leaves unless they are hungry or bored from a lack of “chew time.”

Finally, inform residents of adjacent properties of the danger in feeding fallen leaves. A sign on the shared fence line is also a good idea. A well-meaning but uninformed neighbor may toss a pile of leaves to your horses, thinking he’s providing a special treat.

This article first appeared in EQUUS issue #446, November 2014.