Foot chewing/licking is the cardinal sign of allergies. But, allergies in a puppy THIS young would be incredibly odd - bc she should still be protected by her Momma's antibodies. Because of this, it almost makes me wonder if her Mom had yeast - and that she passed it on to Sadie. I would get her to the vet, explain the symptoms, and make SURE the vet checks feet, between the toes, inside ears, the arm pits, the tummy, the neck - all of those hidden/moist areas where yeast can grow. Yeast is easily passed on to offspring through the birthing canal - so IF the Mom happened to have it, the pups would too. And you would want to catch yeast ASAP, believe me!
