What Horses Can’t Eat: Common Foods That Are Actually Dangerous

As horse owners, we want to give our horses the best care possible. That includes knowing which treats and foods are safe and which ones should be avoided. While horses may seem curious and willing to nibble on just about anything, their digestive systems are delicate and sensitive. Feeding your horse the wrong food can lead to serious health issues, or even be fatal in extreme cases.

In this blog, we’ll explore the most common foods horses should never eat and explain why these items can be harmful.

1. Chocolate

Chocolate has theobromine, a stimulant that is poisonous to horses and should always be kept out of their reach. Even small amounts can affect their nervous and cardiovascular systems. Symptoms of chocolate toxicity include increased heart rate, seizures, and in severe cases, death. Never feed your horse chocolate or any food that contains cocoa.

2. Avocados

Avocados contain a substance called persin, which can be toxic to horses and should be avoided. All parts of the avocado plant, including the fruit, peel, seed, and leaves, are hazardous to horses. Ingesting avocado can cause colic, difficulty breathing, and swelling of the head and neck. Keep avocados far from any area your horse can reach.

3. Onions and Garlic

Onions and garlic, especially in large or consistent amounts, can damage a horse’s red blood cells and lead to anemia. While garlic is sometimes marketed as a natural supplement, excessive use can be harmful. Onion toxicity can occur even in powdered or cooked forms, so check labels carefully.

4. Tomatoes and Other Nightshades

Tomatoes, potatoes, and peppers are part of the nightshade family and contain solanine, a compound that can be toxic to horses. In horses, this toxin can cause colic, decreased appetite, and digestive upset. Green or sprouting potatoes are particularly dangerous, but even ripe tomatoes are best avoided.

5. Caffeine

Drinks and foods containing caffeine, such as coffee, tea, and energy drinks, are harmful to horses. Caffeine acts as a stimulant and can cause an increased heart rate, restlessness, and irregular heartbeat. Make sure horses never consume beverages or leftover food that contains caffeine, as it can be harmful to them.

6. Bread and Other Baked Goods

While not always toxic, bread and baked goods can expand in a horse’s stomach and cause digestive problems. Moldy bread poses a serious risk to horses, as it may contain harmful mycotoxins. These can cause severe neurological symptoms or colic. It’s best to avoid feeding any processed human food to horses.

7. Lawn Clippings

Freshly cut grass might seem harmless, but lawn clippings can ferment quickly and lead to colic or laminitis. In some cases, the clippings may include toxic plants that were unknowingly mowed. Horses should only graze on pasture grass or hay and should not be fed yard waste.

8. Fruit Seeds and Pits

Fruits like apples and pears are often given as treats, but their seeds and pits contain small amounts of cyanide. While a few seeds may not cause immediate harm, large quantities can be dangerous. Always remove the core and pits before offering fruit to your horse.

9. Dairy Products

Horses are lactose intolerant. Their digestive systems are not designed to handle dairy products such as milk, cheese, or yogurt. Giving horses dairy products can lead to digestive issues, including diarrhea and stomach discomfort. Stick to horse-friendly treats that do not contain animal byproducts.

10. Moldy or Spoiled Feed

Any moldy, spoiled, or musty-smelling hay, grain, or feed can be extremely harmful. Mold may carry toxins that can negatively impact a horse’s liver, respiratory system, or nervous system. Always store feed properly and check for signs of spoilage before feeding.

Keeping Your Horse Safe

Feeding horses may seem simple, but understanding what not to feed is just as important as knowing what they can eat. A horse’s diet should be based primarily on forage, such as hay or grass, supplemented with grain or concentrates if needed. When offering treats, choose options like carrots, apples (without seeds), and horse-safe commercial treats in moderation.

If you suspect your horse has eaten something toxic, contact your veterinarian immediately. Early action can make a big difference in preventing serious complications.

Final Thoughts

Knowing what foods are dangerous for horses is an essential part of responsible horse ownership. Avoiding harmful treats, reading labels carefully, and sticking to a consistent and safe feeding routine will help keep your horse healthy and happy. If you're unsure about adding something new to your horse’s diet, it’s best to consult an equine veterinarian first.