[YorkOfTheShire]

I'm not a vet. Is it his actual leg he's biting at or the paws? Something else might be going on if it's his paws...might have a nailbed fungal infection (check for flakey, brittle nails or pink tint near the base of the nail, or if they're discolored).

I would at the very least make sure there's allergy testing done. If it's not an allergy my next guess is something neurological since his legs bother him also.

I know you don't have the money right now to take him to a vet, but I would take him as soon as possible, as from your post it sounds like it's progressing (whatever it is). Also - if I may suggest...try looking into pet insurance. You pay a premium but you can choose to pay it monthly instead of annually or bi-annually and the peace of mind you get from it is worth it. Some pet insurance companies will offer you a zero deductible, but you'll have a higher monthly premium. Might be something you (may) want to look into.

I hope Sampson gets the care he needs and they are able to rid him of his pain and/or annoying sensations he's getting.

Time to go - puppy just woke up.