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Poor Mason, this sounds so uncomfortable for him. My first recommendation, of course, is to have him examined by his Vet. You will want to be very particular about anything you apply to Mason's paws because his first instinct will be to lick it off, thus ingesting the substance. I've used olive oil, but not on paws. This doesn't fit in the nonoily/greasy category, though, so you might would find yourself with little oily paw prints all over the place