I had a peke-a-poo who licked her front paws incessantly, to the point where she caused huge blisters, sometimes as big as a silver dollar, that my vet instructed me to soak in Epsom salts to get them to break open. She always felt so much better after they were open; then I'd bandage them and she tear the bandage off w/in minutes. LOL We never knew for sure what caused it; my vet thought possibly lawn treatment chemicals but since she licked only her front paws instead of all of them, he admitted that might not have been the reason. She lived to be 18 1/2 and it wasn't until she was 14 1/2 that the licking stopped but that's also when we bought a new home and we didn't use lawn chemicals there because we had much more property to treat. Good luck w/this. My dog's paws got pretty sore and I hope that isn't the case w/your dog.