Strange Eating Habits: Pica in Horses

Strange Eating Habits: Pica in Horses

The secrets behind horses that eat unusual substances, including bark, dirt or manure.

two grazing horses in pasture in autumn (Credit: Canva)

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Presented by AQHA Corporate Partner SmartPak

The eating of unusual substances – called pica – has been observed in horses of all ages, breeds and sexes. For horses who eat dirt, bark or manure, these behaviors are typically indications of a deficiency in a horse’s diet or activity. 

Geophagia (Dirt-Eating)

Some experts believe dirt-eating is derived from horses craving minerals in the dirt, as the practice has been observed in both domesticated and wild horses. 

Eating dirt is typically safe, with the exception being if too much sand is ingested, which could trigger sand colic. Feeding hay on mats or in nets and adding psyllium to the diet can help manage the risk of sand colic.

Continue reading about geophagia.

Coprophagy (Manure-Eating)

Eating manure can be a normal activity of foals, from about 1 week to 2 months old. Most experts agree manure-eating populates the foal’s GI tract with beneficial bacteria. Another theory suggests that ingested parasite eggs stimulate the foal’s immune system. 

Manure-eating in adult horses, however, may indicate a lack of nutrients or roughage.

Continue reading about coprophagy. 


Eating bark can be another indication of boredom or lack of roughage in a horse’s diet. 

To protect the trees you can install woven wire around the trunks up to a height the horse cannot reach above. This doesn't solve the horse's problem but it does prevent damage to the trees until the problem – be it a lack of roughage or boredom – can be resolved.

Solutions for Pica in Horses

It's not uncommon for horses kept in stalls, paddocks or dry lots to become inventive with their behavior. Horses typically graze 16-20 hours per day and when they are unable to do that, they find alternative sources of fiber and something to occupy their time.


Provide plenty of roughage for both entertainment and gut health.

If you feed a very high quality hay, like alfalfa, you may want to switch to a higher fiber hay with lower nutritional value such as a grass hay. To extend the amount of time hay is in front of your horse, split feedings up so the horse is provided hay at least three times per day or consider a slow feeding hay net. 

Muzzles and slow feeders can help overweight horses or those who should be on limited roughage. 

Vitamins and Minerals

Ensure the horse’s vitamin, mineral and protein needs are being met or supplement with fortified grain or a multi-vitamin/mineral. 

Curbing Boredom

Consider increasing riding time or introduce a companion such as another horse, a pony or even a goat. Horses are herd animals and need another animal with which to bond. 

Seek Veterinary Assistance

Horses that show any other behavioral or physical signs – such as colic, weight loss or performance issues – should be examined by a veterinarian to determine if a medical condition may be present.

About the Sponsor: SmartPak

As the leading supplement retailer, AQHA Corporate Partner SmartPak has had thousands of conversations with horse owners dealing with horse health problems. Hearing the challenges the horse owners face trying to find the right supplements for their horses led SmartPak to create its own brand of targeted supplements solutions.

Learn more about SmartPak – the AQHA official online retailer of horse care, gear and supplements – at