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What Not to Feed

What Not to Feed

There are actually a number of food items that can be dangerous for horses so it’s worth knowing this list – and putting up signs to stop well-meaning strangers from ‘treating’ your horses when they are in the field.

As mentioned earlier, there are a number of toxic plants that can cause severe, and occasionally fatal, health issues for horses. Horses are also sensitive to high-sugar diets, with too much sugar leading to a number of potential health problems including laminitis, insulin resistance, and equine metabolic syndrome (EMS).

Also don’t feel the urge to humanise your horse’s eating habits. Chocolate contains theobromine, which is toxic to horses. Avocados contain persin, which is also toxic. Caffeine is a no go, and onions and garlic can cause anemia and digestive problems.

Dangerous plants:

  • Ragwort

  • Yew

  • Oleander

  • Nightshade (including Deadly Nightshade and Horsenettle)

  • Foxglove

  • Bracken fern

  • Red maple (wilted leaves)

  • Black walnut (shavings or bark)

  • Rhododendron and azalea

  • Jimsonweed

  • Tansy ragwort

  • Poison hemlock

  • Buttercups

  • Larkspur

  • Water hemlock

  • Locoweed

  • Castor bean

  • Kentucky bluegrass (endophyte-infected varieties)


This is not an exhaustive list and there are plenty of other dangerous plants out there, so find out what plants are local to you and check if they are toxic to horses.


Common food items that are toxic to horses:

  • Chocolate

  • Coffee and caffeine

  • Onions and garlic

  • Avocado

  • Tomato leaves and stems

  • Potatoes (particularly green parts or sprouts)

  • Rhubarb

  • Foods containing xylitol (a sugar substitute)

  • Alcohol

  • Moldy or spoiled food

  • Foods high in sugar or artificial sweeteners

  • Bread and other baked goods

  • Dairy products (milk, cheese, yogurt)

  • High amounts of grains or processed feeds

  • Foods with high levels of salt

  • Foods with added preservatives or artificial additives


Foods that ought to be treated with caution include:

  • High-sugar fruits, such as apples and watermelons

  • Molasses-based treats or feeds

  • Cabbage, broccoli, and cauliflower; cruciferous vegetables, which can be gas-forming and therefore could lead to digestive upset

  • Bread, while small amounts won’t do any harm, it is not generally recommended to feed horses bread as it could cause digestive issues

  • Excessive intake of grain-based feeds. Feeding excessive amounts of any feed can lead to digestive upset, colic, or metabolic issues.

  • Freshly mown or wilted grass. While not considered toxic it can be dangerous for reasons that include: the clippings becoming compacted in the digestive system, potentially causing blockages or colic; fermentation, which can bring on gas in the digestive system, which can, again, cause discomfort or colic; and the presence of potential chemicals and contaminants, especially if the grass has been treated with herbicides and pesticides etc.


Remember, if in doubt, leave it out – and call your equine nutritionist. And if you suspect your horse has eaten something toxic, contact your veterinarian immediately.


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