Why Do Horses Eat Bark Off Trees?

You may have, on occasion, witnessed your pet eating grass or soil out of the garden. When we see our animals eating something unexpected, we often want to know why, and there is usually a pretty good explanation.

Why horses eat the bark off of trees can be explained by one of three reasons. First, the horse may be lacking something in their diet, usually as a vitamin or mineral, which they are finding in the wood. Second, the horse may have developed a behavioral issue caused by boredom or frustration or, lastl the horse may simply have developed a taste for wood.

Whatever the reason, eating the bark off of trees can cause a host of problems down the line. As such, it’s crucial to identify the reason for the bark-eating behavior as well as find ways to curb such practices.

Quick Navigation

Why Can’t I Let my Horse Eat Bark?

One of the first questions you may be wondering is why can’t you just let your horse eat bark if that’s what they want to do? Well, there are several sound reasons why you should stop your horse from chomping down on trees.

Researchers at the Australian Equine Science Symposium noted that horses are not only grazers, eating grass, but also browsers, meaning they eat shrubs and leaves (source).

While horses may be inclined to eat shrubs and leaves off of trees, there are certain problems associated with allowing bark into their regular diet.

Firstly, eating wood is not usually limited to trees; horses who eat bark will also often eat fence poles. This behavior can be both costly and destructive and may require you to re-fence an area or relocate a horse.

Additionally, if a horse successfully strips the bark from around the entire trunk, the tree will not survive.

Secondly, eating bark and other wood can cause damage to the horse’s teeth. Additionally, you run the risk of splinters and pieces of wood lodging in the horse’s mouth and throat.

Lastly, certain types of trees —  such as oaks, yews, and maples —  are toxic to horses. You may not be an expert on poisonous trees, which is a potentially fatal risk, and another reason you should do your best to stop your horse from eating bark unless you know the tree is safe (source).

It’s Diet-Related

The first thing you might need to ask yourself if your horse has started eating the bark off of trees is whether it’s diet-related.

Often animals who eat things that are not in their usual diets, such as grass and soil, do so because they have a sort of deficiency in their diet.

If you think that your horse’s behavior may be diet-related, then it’s essential to call in a veterinarian to assess your horse’s diet and their overall physical state.

After looking over your horse, the veterinarian may find the horse is suffering from a deficiency in minerals or vitamins.

In addition to eating bark, other signs of a deficiency in a horse’s diet may include a coat which is lackluster and dry, or the horse suffers from acute or recurrent illnesses, doesn’t perform adequately, or is eating soil (source).

How to Solve a Deficiency in Your Horse’s Diet

Your vet may have a recommendation on addressing the deficiency in your horse’s diet. Alternatively, there are a few things you can do.

One simple option is you can add a supplement to their diet once a day at mealtimes. Another option is to bring a mineral “lick” into the paddock for the horse to eat. Essentially, a “lick” is a vitamin-enriched edible block.

Some licks are solely mineral-based, while some are molasses-based or infused with oils and seeds. Licks are also great ways to keep horses busy.

Another way to address diet deficiencies in horses is to plant herbs and other edible weeds in the paddock for the horses to eat.

There are many herbs for pastures that you can plant and which provides a natural way of bringing vitamins into your horse’s diet (source).

Here are some plants which will add minerals and vitamins to your horse’s diet:

  • Chamomile: a natural source of calcium.
  • Sunflowers: a natural source of phosphorus, which is good for the nervous system.
  • Carrots:  a natural source of sodium.
  • Parsley: a natural source of potassium, which is good for muscle development.
  • Dandelions: a natural source of magnesium and iron.
  • Alfalfa: a natural source of vitamin C, B vitamins, phosphorus, and zinc.
  • Meadowsweet: a natural source for gut health.

Studies done at the Queensland Agricultural College in Australia showed that horses might be lacking fiber in their diets, which is why they eat the bark from trees (source).

Introducing more fiber and roughage into your horse’s diet may be a way in which to help curb their tendencies to eat the bark from trees.

For more information on why horses might eat unusual things, you may want to check out our article on why horses eat manure.

It’s a Behavioral Issue

If your veterinarian has ruled out the bark-eating as a dietary issue, then it may be a behavioral one. Bear in mind that if your horse is not just eating bark but also wooden fence posts, then that increases the likelihood that it’s a behavioral issue.

Horses usually develop behavioral issues out of boredom or frustration. Horses are intelligent creatures and therefore require stimulation.

If it’s a behavioral issue, then you need to try and put a stop to it before it develops into an ongoing habit. You can call in a specialist who deals with horses who have such behaviors, or there are several other steps you can take.

How to Curb a Bad Behavior in Horses

If your horse is behaving unfavorably, there are methods that you can employ to discourage them from such practices.

Install a Slow Feeder

You can install a “slow feeder” for your horse, which is a mechanism designed only to release a certain amount of hay at a time, making a horse’s meal last longer and thus reducing the chances of boredom (source).

Eliminate or Limit Access to Trees

You can limit their access to wood by removing the trees around the paddock. However, it’s important to remember that in the summer months, horses do require shade.

An alternative would be to remove the horse’s access to trees, which could be done by creating their paddock in another location or cornering off a part of the paddock.

Image by Michael Gaida via Pixabay

Replace Fence Posts

If the horses are eating the wooden fence posts, then you may want to consider replacing them with an alternative such as PVC piping.

Increase their Exercise Routines

If your horse’s behavior is caused by boredom, then a rigorous exercise routine will help to keep them out of trouble. Exercise is an excellent means to keep your horse physically and mentally occupied, and it limits the time they have to exhibit destructive behaviors.

Introduce Toys to Keep them Entertained

There’s a perfect reason that someone coined the phrase “horsin’ around.” Horses enjoy playing just as much as the next animal, so if you find that your horse is bored or frustrated, you can offer them some toys to keep them occupied (source).

There are many equine toys on the market, many of which are ball-related.

If you are interested in knowing more about horses and their behavior, then you may like to discover why horses foam at the mouth.

Your Horse Has Developed A Taste for Wood

If you have tried to deter your horse from eating bark and other types of wood and failed, it may be because your horse has now developed a taste for wood. At this point, you may be wondering, what do I do now?

While this is the most challenging stage at which to try to eliminate the behavior, there are still some things you can do.

Run an Electric Wire around the Paddock

Placing an electric wire around the paddock will ensure that the horses are unable to access both the trees and the wooden fence poles. Of course, this is only a solution if the trees are outside of the paddock itself.

Treat the Wood to Make it Unappealing

Treating wood to make it unappetizing is a good way to deter horses, albeit a time-consuming one.

You can treat the bark on the trees and the wooden fence poles with a paste made of mustard, bitter aloe, or crushed up cayenne pepper. This paste will hopefully deter the horses from eating the wood.

Make Sure your Horses Aren’t Eating Toxic Trees

If all else fails and you cannot get your horse to stop eating bark, then make sure the horse doesn’t have access to toxic trees (source).

Unfortunately, you cannot rely on horses to discern which trees are good and which are bad, so it’s better just to make sure that they don’t have access to them.

Also, make sure to check your horse’s teeth and gums regularly to make sure that none of the bark or wood has been trapped there.

Here are some trees known to be toxic to horses (source):

  • Black walnut
  • Red maple
  • Cherry
  • Plum
  • Peach
  • Oak (especially acorns)
  • Horse Chestnut
  • Oleander
  • Yew

Image by Michaela Kliková via Unsplash

Final Thoughts

Whether your horse is eating bark due to a mineral definitely, a behavioral issue, or is doing so out of a bad habit, you must do your best to curb the behavior. Luckily, there are several steps you can take to deter your horse from eating bark and other types of wood.