A recent study found that horses with pica–a propensity for consuming non-food items–have lower iron and copper blood levels than horses who restricted themselves to food items only. According to researchers from Turkey, "prophylactic use of iron and copper supplements in horses may be beneficial to prevent pica."

Horses with pica can lick or mouth foreign substances or, in some cases, actually ingest the materials. Some of the more common forms of pica in horses include chewing bones (osteophagia), ingesting feces (coprophagia), chewing and eating wood (lignophagia), and eating soil or sand (geophagia). Pica is problematic as it can cause colic and tissue damage due to migrating foreign bodies.

While the underlying cause of pica remains unknown, a multitude of hypothesis exist such as underlying health problems, dietary deficiencies, and nervous system disturbances, among others.

Control of pica has traditionally involved providing salt and mineral supplements, feeding fresh grass, greens, and carrots, providing higher levels of hay or long stem forage, feeding at the same time every day, regular deworming, feed analysis, physical examination and routine blood work performed by a veterinarian, and cross-tying horses in their stalls to prevent the untoward behavior