Why Does My Horse Eat Mud?

We’ve all heard the saying ‘a little bit of dirt never did anyone any harm’, well horses have taken that phrase to the extreme! Not only do they regularly eat mud and dirt they actually need it as part of their natural diet. As well as being an essential part of their diet, horses also need dirt to help keep the chewing surface of their teeth relatively smooth. You may be surprised to know that there’s actually a proper scientific word, geophagia (or geophagy), to describe eating mud, dirt or soil.

What are the benefits of horses eating mud?

There are a lot of minerals such as iron, potassium and calcium in soil and while it’s possible for horses to get these from their feed or from supplements, their digestive system is able to process the minerals from the soil much more effectively and more quickly. It’s not necessarily just the soil that the horse is eat though, they’ll also dig up some plant roots because of the microbes in them. These microbes, such as bacteria and fungi, can have a positive effect on a horse’s digestion.

You might not realise it but dirt is made up of course particles that act as a natural rasp for your horse’s teeth, keeping the chewing area smooth. In fact, horses that spend most of their time in a stable or stall and aren’t able to eat much dirt have to have their teeth floated far more frequently than horses that are able to regularly eat dirt.

Self medicating with dirt

Some horses, when they have an upset stomach, will choose to eat dirt as a way of making themselves better. This idea isn’t quite a crazy as it sounds because soil contains a certain amount of clay which is super absorbent. The clay will then ‘mop up’ toxins, acids and even some viruses from the horses gut. Once bound to the clay they’ll naturally make their way out of the horses body harmlessly.

Can eating dirt be a bad sign?

While horses can and do get a lot of benefits from dirt it’s not always a good sign when they do. Horses that are dehydrated will eat dirt because the water and salt it contains will help to quench their thirst and keep them hydrated. If a horse has access to plenty of fresh clean drinking water then he won’t resort to eating the dirt out of thirst.

Likewise with lack of water, horses that are lacking fiber in their diet will eat anything they can find to top their fiber levels up. While they do eat things such as shavings and fences, they’ll also eat dirt to increase their fiber intake. You might not think there’s any fiber at all in dirt but when you think about the leaves, plants and other foliage that breakdown into the soil it’s easy to see why they do this. Making sure your horse has enough fiber will stop him needing to increase his levels and therefore stop him eating dirt for fiber.

Sadly eating dirt can also be a sign of a horse that is hungry or bored, if a horse doesn’t have enough food then he’ll eat whatever is around, whether its dirt or poisonous plants, just to stop feeing so hungry. Likewise if he’s bored he’ll eat the dirt as a way of passing the time and distracting himself from the boredom.

While eating dirt is perfectly normal you should still investigate if you horse does suddenly start eating it or eats a lot more than he normally does. Any change in your horse’s behavior shouldn’t just be brushed aside as it could be a sign of something else.

Are there any side effects to my horse eating dirt?

As a general rule no but it does depend on the amount of dirt they’re eating really and the reason why they’re eating it. Horses eating a ’normal’ amount of dirt are very unlikely to suffer any side effects at all but if a horse is eating it because they’re hungry that’s a different matter. In this case they’re far more likely to eat a large amount of it which can cause some stomach or digestive problems. Eating an excessive amount of dirt can cause impaction colic if not addressed quickly.

There is also some evidence that eating a lot of dirt may cause gastric ulcers. While not at all conclusive there has been a lot of research carried out as to the behaviour of horses with ulcers, the studies noticed that in some cases horses who did eat a lot of dirt will suffered from gastric ulcers. That’s not to say that the dirt is causing it because all of the horses in the test already had ulcers. There is another train of thought that suggests the horse may be eating the dirt to help sooth the ulcer, although this hasn’t been proven either way.

To prevent your horse from eating too much mud though make sure he’s not doing out of boredom or hunger and if you think he’s showing signs of impaction colic then you call the vet immediately. You can read more about colic and how to treat it in this recent article I wrote.

Why does my horse eating manure?

Eating manure (or coprophagy as it’s officially known as) isn’t the same as eating mud. Manure does contain a few nutrients that weren’t digested the first time but other than that a horse won’t usually get any real benefit from eating it. Some horses do eat their manure in an attempt to increase they microbial count in their cut but the vast majority of horses that do eat manure will do it for negative reason. 

  • Lack of proper food – If a horse isn’t getting enough natural food or the food they are getting doesn’t have the right nutrients then they might start to eat their (or other’s) manure. They’re trying to either stop their hunger or increase the nutrients they have.
  • Boredom – As with a lot of other vices horses can pick up, eating their manure can result from boredom. If a horse nothing to stimulate him he’ll develop bad habits such as weaving, cribbing or even eating manure.
  • Stress – Horses are creatures of habit and can get really stressed and upset if they don’t have a routine, as with boredom they can develop bad habits like eating manure.
  • Nervousness – Much like humans biting their finger nails when they get nervous, horses can develop habits to distract them from whatever causing them to be nervous.

If your horse does start to eat manure then first of all make sure that he has enough nutritional food and then look at addressing the underlying issue. If he’s stressed or nervous then try to help him over come that, if he’s bored then consider investing in some toys or turn him out with other horses more often.

Is my horse okay eating sand?

While small amounts of sand will help your horse keep his teeth smooth eating too much sand can be bad for him. Unlike soil which will generally move through your horse easily, sand is quite grainy and tends to settle in your horse’s stomach and digestive tract. Small amounts will be ‘washed’ out with other foods but too much can start to cause a blockage in the large intestine. 

If you live in a sandy area you can minimise the amount of sand he consumes by not feeding him on the ground. Feed hay in racks or bins to keep it off of the floor and don’t give him ground feeders. You can’t stop your horse eating the sand as he grazes in his paddock but monitor him and keep an eye out for signs of colic. Some vets will recommend feeding your horse psyllium to get all of the sand out of his digestive tract, although opinion as to whether this really works is mixed.

Conclusion

Next time you see a horse eating dirt don’t try and stop him thinking its bad for him, instead allow him daily access to it! That way he’ll get all of the minerals he needs while also keeping his teeth in check. Feeding your horse hay from the ground while he’s in the paddock will also help to encourage this natural behaviour although if your soil is sandy don’t do this.

If you’re worried that your horse is eating the dirt because he’s bored them why not give him a boredom busting toy to pay with. This will stop the boredom but will also prevent him from eating the dirt out of boredom.

I hope you found this article helpful, if you did I’d be grateful if you could share it please as it would really help me.