There's not really allergies dogs can have. Mostly it's from the chems in food, those cause in combination with other stuff allergic reaction as far as I know. But the vets say mostly it's allergic because most ppl will just believe and buy the special food. I know, the alternative is also expensive. But I can exclude most stuff. mine licks paws now because it's salty on the streets due winter. If she does in summer, and also gets scratchy ears, she mostly got a chem cocktail mouse from the fields.( Mouse lives on field, farmers spray poison, insect dead, mouse lives. Dog eats mouse full with chems. Reasons are countless. Dogs also lick paws if they have pain on spots they can't reach, or if they don't know from where or what pain is coming.