Q:My 9-year-old gelding constantly licks one spot in his paddock. As far as I can tell, there’s nothing unusual about this spot—it has the same clay-like soil we have everywhere in this area. My horse is otherwise healthy and well-behaved.

I’ve had people tell me that my horse is seeking some particular nutrient that his diet is missing, but he’s on a well-regarded commercial feed and gets lots of grazing time in spring and summer, and hay in winter. He also has access to a salt block.

Other people have told me that soil eating is a stereotypy like cribbing, but he doesn’t seem stressed out to me and he doesn’t have any other undesirable habits. The dirt patch is in the middle of the field, so it would be hard to fence off. I suppose I could get a giant boulder to put over it to deter him. Is that necessary or is there something else that I should do?

A: Your horse is most likely licking/eating the soil (also known as geophagia) due to boredom. He doesn’t need to be stressed or unhappy to develop this habit. This type of behavior is similar to nail-biting in people—they aren’t necessarily unhappy or stressed but simply develop this habit over time.

The theory that horses consume soil because they are missing an essential nutrient is usually a myth. In your horse’s case, this explanation is especially unlikely given that he receives a commercial feed, which will be nutritionally balanced, and he has access to a salt block.That said, pay attention to his feed intake. If your horse’s ideal feeding rate is five pounds per day and you are only providing two pounds, then he would likely be deficient in some nutrients. I would consult an equine nutritionist to make sure his ration meets his nutritional and energy needs.

Regardless of the reason for your horse’s geophagia, you’ll want to take precautions that will limit this behavior. Even soil that is not sandy can have deleterious effects on the equine gut similar to sand colic. I would start by making sure your horse has free choice access to forage (pasture or hay) at all times. Increasing the amount of exercise he gets and/or giving him a pasture mate may also help.

Finally, you can try sectioning off the area in the pasture where he consumes the soil. Alternatively, you can sprinkle the area with cayenne pepper. This may help break the habit or he may simply find another area where he can continue indulging in this behavior.

James Lattimer, PhD
Assistant Professor, Equine Nutrition
Kansas State University
Manhattan, Kansas