If your horse is healthy, isn't on any medication, and likes citrus fruit, an occasional orange or grapefruit will be a welcome treat. | Photo: iStock

Q: Can horses eat citrus? My horse saw a grapefruit, got excited, and grabbed and ate it. He bit off part of the rind, squeezed it, and slurped up the juice and pulp. It definitely looked like he had eaten grapefruit before. I tried looking online, but found contradictory opinions. —Roberta, Los Angeles, California

A: I know many horses who enjoy eating citrus fruit everything from the whole fruit to the peel. Not all novel foods horses enjoy eating are necessarily good for them, though. Luckily for most horses citrus is unlikely to have any detrimental effects and might offer potential benefits beyond vitamin C.

Perhaps surprisingly, there’s research looking at feeding orange peel extracts to horses. Orange peel and other citrus peels contain flavonoids that have potent antioxidant properties and scavenge free radicals and reduce oxidative stress. Some of the compounds found in citrus peel extracts inhibit the expression of tumor necrosis factor alpha (TNF-α), a cell-signaling protein or cytokine that is involved in systemic inflammation. Therefore, reducing TNF- α could reduce inflammation