The most common cause of foot-chewing is allergic disease.
It makes sense when you think about it: since so many allergens are plant-based, and dogs walk on grass, if they’re allergic to grass their feet will be irritated. And chewing and licking feels good to dogs, so they lick their feet when they are irritated.
Foot chewing and licking can also go along with food allergies. For this reason, we’ll often recommend a change to a hypoallergenic diet when a dog is licking its feet. Sometimes this takes care of the problem, but unfortunately, most allergic dogs have an environmental allergy, and the food doesn’t always solve the problem.