Fauquier County is horse country, and a lot of the properties we work on have pastures, paddocks, or fence lines bordering wooded areas. Most horse owners know to keep an eye on their feed, but far fewer realize how many common landscape and woodland trees pose a real risk if a horse gets to the leaves, bark, or wilted branches.

This isn't a complete veterinary reference — always talk to your vet about your specific property and horses. But here's what we, as arborists working on horse properties across the region, think every owner should know.

Why Wilted Leaves Are Often the Real Danger

Here's the part that surprises a lot of people: for several of the most dangerous species, it's not the healthy, growing leaves that pose the biggest risk — it's wilted, damaged, or fallen ones. A branch that snaps in a storm and lands in a pasture can become more toxic than the same leaves would have been on the tree, which is exactly why storm cleanup near pastures isn't optional.

The Trees to Know

High Risk

Red Maple

Wilted or dried leaves can cause a serious form of anemia in horses. Extremely common throughout Virginia, which makes it one of the most important species to watch near pastures.

High Risk

Wild Black Cherry

Wilted leaves and damaged bark release compounds that can be acutely toxic. Common along tree lines and fence rows throughout the county.

Moderate Risk

Black Walnut

Most commonly a hazard through contaminated shavings or bedding rather than direct grazing, but the tree itself is worth keeping well clear of paddocks.

Moderate Risk

Oak (Acorns & Young Leaves)

Large quantities of acorns or young spring leaves contain compounds that can cause problems, especially in years with a heavy acorn drop.

Severe Risk

Yew

Ornamental yew is highly toxic in even small amounts and is sometimes planted near homes without considering nearby pastures — worth checking for on any horse property.

Signs Something May Be Wrong

If a horse has access to a toxic species, watch for lethargy, loss of appetite, discolored urine, labored breathing, or general distress. These symptoms are not specific to tree toxicity alone — but if there's any chance of exposure to one of the species above, don't wait to see if it resolves on its own.

If you suspect poisoning, call your veterinarian immediately. This article is not a substitute for professional veterinary guidance.

Managing the Risk on Your Property

The most practical approach isn't necessarily removing every tree on the property — it's knowing what's near your fence lines and pastures, and staying ahead of storm damage. A few things worth doing:

  • Walk your fence lines and identify any high-risk species growing near or over pasture areas
  • After any storm, check pastures for fallen branches before turning horses back out
  • Consider removing or relocating high-risk trees that directly overhang paddocks
  • Keep wood chip or mulch sources away from paddocks if they could include black walnut

If you have a tree near your pasture that you're unsure about, we're happy to take a look. See our tree removal page for how we approach removals near fencing and structures, or our tree trimming page if the tree just needs its overhanging branches cut back rather than full removal.

Frequently Asked Questions

Yes — wilted or dried red maple leaves are one of the more well-documented causes of serious toxicity in horses. Given how common red maple is throughout Virginia, it's worth specifically checking for near any pasture.
Not necessarily — the real risk is proximity to pastures and access after storms. A tree well away from any paddock is a much lower priority than one directly overhanging a fence line.
Before turning horses back out, ideally. Wilted leaves from a freshly fallen branch are often at their most toxic in the hours and days right after falling.
Call your veterinarian right away rather than waiting to see if symptoms develop. Time matters with plant toxicity, and a vet can advise on next steps specific to your horse.