What Can Horses Not Eat [GUIDE]

The Horse as a Companion Animal

When you think of horses, what comes to mind? The open fields? The racetracks? Or pets? Do you think about what can horses not eat or whether certain foods, like chocolate, are bad for horses? 

How about companionship? Owning a horse is more like having a companion whose overall quality of life is dependent on you. Therefore, it is critical to ensure that the foods you give your horse are not harmful.

What Can Horses Not Eat – a List

1. Chocolate

Is chocolate bad for horses? Yes, absolutely! Chocolate contains a compound called theobromine. This compound is extremely poisonous to horses that consume it in large amounts. This compound can cause internal bleeding, seizures, and metabolic derangement. Chocolate also contains caffeine, which is also poisonous to horses and dogs. 

2. Caffeine

Giving even a minute amount of caffeine to your horse, even in rare instances, can adversely affect your horse. It can invariably cause irregular heartbeat problems. Therefore, you should avoid giving your horses any food that has caffeine in it. 

3. Potatoes

Potatoes do not count as horses’ food. It’s best to avoid giving potatoes to your horse (although we know some horse owners who occasionally feed them the potato chips as a snack). Doing this poses a health risk to your horses if the potatoes are moldy or too “green.” Your horses can succumb to toxicosis or choke on a tough, unripe potato. 

4. Avocado

Avocados can be poisonous to horses if ingested. Any part of the avocado, be it the meat of the vegetable, the skin, or leaves, can be harmful to horses. The avocado’s pit (or stone) can also be a choking hazard.

5. Fruit in Large Quantities

Fruits like apples are an excellent treat for horses. However, too much of a good thing can be harmful. Your horse eating apples too many times or taking in a lot of other fruits can cause colic, which may lead to laminitis (founder). Most horse owners will not feed their horses more than two pieces of fruit at a given moment. 

Horse owners should avoid feeding their horses large quantities of fruits. Look out for your horses getting to windfall fruits from trees or someone dumping a basket of spoiled fruits for your horses to find.

White horses on the field eat apples

6. Rhubarb

Rhubarb is known to cause injuries to horses’ urinary tract and digestive systems. In extreme cases, it can result in kidney failure. Rhubarb contains calcium oxalates. Calcium oxalates are poisonous to horses because their digestive systems cannot break down these compounds.

7. Fruits with Pits (Stones)

Fruits with pits, like whole peaches, avocados, and cherries, can be dangerous for a horse because they could choke on them.

8. Bran Mashes

Horses need a lot of fiber in their diets. However, adding too many bran mashes can affect their gut flora and cause diarrhea, among other digestive problems. Bran has little nutritional value, so they are recommended only as an occasional treat for horses.

9. Cauliflower, Cabbage, Broccoli

Feeding your horse any of these three vegetables in excess can lead to terrible gas and colic problems that could adversely affect their health and quality of life. It is better to avoid these vegetables to be on the safer side. 

10. Cattle Feed

While cattle feed can be very nutritious and healthy, they are very toxic to horses. Cattle feed contains supplements that are good for cattle. Drugs like Rumensin are routinely added to cattle feed, and these drugs can be deadly for horses. It is advisable to buy feed from providers that deal exclusively with horse feeds.

11. Meat

Horses are herbivores and have herbivore digestive tracts, and do not need meat to survive. However, horses can and will sometimes eat meat. You can also train horses to eat meat. This doesn’t mean that a regular diet of meat in the long term is a good thing. 

A horse’s digestive system is not designed to have any kind of meat processed through it. Therefore, a diet high in meat is inadvisable since we do not know the long-term effects on most horses.

12. Dairy Products

Horses can be lactose intolerant. Dairy products are not necessarily poisonous to horses. However, there is a high possibility they could eventually cause digestion issues. While milk may be nutritious and essential for foals, it is advisable to stop feeding horses milk and other dairy products once they are grown up.

13. Alsike Clover

In either hay or pasture form, Alsike clover is poisonous to horses. Eating alsike clover may trigger severe skin reactions to sunlight and cause mouth sores. Eating alsike clover may also cause problems like colic, big liver syndrome, and diarrhea. Prolonged exposure to alsike clover can also lead to liver cirrhosis. 

Alsike clover is common in pastures. You can tell it apart from red clover because it doesn’t have the distinctive white mark on its leaves as the other clovers do. If your horse occasionally eats a few stalks of alsike clover, it’s probably okay since low levels of the toxin are harmless, but prolonged consumption or a large amount at once may cause problems.

14. Onions and Garlic

Garlic, onions, chives, and other vegetables belonging to the family of plants called the “allium” family should be generally avoided. These plants are poisonous to horses because they can damage red blood cells and lead to sickness. 

15. Silage and Haylage

Horses are very sensitive to botulism. An infection can lead to paralysis and death. Hay is baled at a high moisture content and is wrapped in plastic, an ideal environment for botulism to grow. 

How hay is cut and baled, if done improperly, can lead to the risk of botulism poisoning. Poultry manure, small animals, and soil carrying botulism can be baled into the hay, contributing to the growth of the bacteria. However, there are definite benefits to feeding horses with these fodders, like higher nutritional value and low dust.

16. Tomatoes

Tomatoes are tasty and nutritious for humans, but not so for horses. Tomatoes are poisonous to horses. They contain multiple toxins, though the toxicity level is low. If a horse eats tomatoes, it can cause an increased heart rate, colic, and other dangers.

Horses eat a pile of tomato

17. Moldy or Dusty Hay

Feeding your horse dusty hay can cause damage to your horse’s lungs. Hay with mold is also dangerous for horses to eat; it can be toxic, cause colic and respiratory diseases like heaves.

Horses Eating Hay

The Final Neigh

Horses are more than pets; they are companions that require care and respect. It is, therefore, necessary to put a lot of thought into taking care of them, especially when it pertains to what they eat. Horses are herbivores, and as such, they need a specific kind of diet. 

Horses’ food must contain a lot of fiber to keep their sensitive digestive tract working. Feeding horses the wrong kind of food adversely affects the health and well-being of the animal. A poor dietary regime can lead to many costly health complications that will affect the animal’s quality of life. 

It is, therefore, necessary to pay particular attention to the foods that are poisonous to the health of the horses.