If you are a person that loves salads, you may have wondered whether your horse can eat lettuce or not. Lettuce, especially, iceberg lettuce, is a vegetable that is often cautioned against for many smaller animals. But why? And can horses eat lettuce?
Can Horses Eat Lettuce?
One issue with lettuce, especially wild lettuce, is that is contains a milk-colored liquid called Lactucarium. This milky liquid is known as lettuce opium. Lettuce opium is most often found in Lactuca virosa, near the base of the lettuce stems, and it is poisonous to many animals. Wild lettuce, also known as bitter lettuce, is a common weed in Europe and some parts of the United States. The lactuca virosa in wild lettuce has some analgesic characteristics and acts like a sedative.
Edible lettuce is called Lactuca sativa and does not contain lactucarium. Unlike wild lettuce, iceberg lettuce includes a chemical called lactucin, which is an element of lactucarium, but doesn’t have the same effects. So, although your horse may show some behavior changes if they happen to get into some wild lettuce or bitter lettuce and eat it, they shouldn’t have any of these issues with edible lettuces like iceberg, romaine, etc.
The reputation for lettuce being harmful for small animals like guinea pigs, hamsters, and even some dogs is legitimate but not because of Lactucarium. Edible lettuce such as iceberg lettuce can give animals diarrhea, cause gas and bloating, and make them sick or even be fatal.
Can Horses Eat Iceberg Lettuce?
Iceberg lettuce has little nutritional value and can be especially bad for young rabbits who aren’t used to eating green foods. Like any food fed directly from the refrigerator, lettuce can also cause digestive problems for animals. The same is true for wet lettuce leaves. Feeding your animal, including your horse, wet leaves, can cause bloating. To be safe, never feed any animal lettuce that has become wilted or slimy.
So, can horses eat lettuce safely? Your horse is so large it probably won’t harm them to eat some lettuce of any variety. A horse would need to eat a large quantity of wild lettuce or lactuca virosa to ingest enough of the lactucarium to cause problems.
If you do decide to try feeding your horse edible lettuce, consult first with your vet to get their opinion on how it may affect your horse. Once you have your vet’s approval, feed your horse lettuce in small quantities and watch them carefully for any changes in behavior that could signal a problem. If your horse eats iceberg lettuce and likes it and you see no affects, you can try it again several days later.
When your horse eats lettuce, don’t give them any other foods other than their normal diet of hay, grain, and fresh water. Since the issue with horses eating iceberg lettuce is bloating and diarrhea, watch carefully for any behavior changes that may indicate your horse is having these problems. By making lettuce the only new food your horse is eating, you will know lettuce is the cause of any issues.