Are you sure hes biteing it and not licking it..
The reson i am saying this as are peggy was also doing this befor the wife had her hair cut this week now we can see what she is doing ....Looks like peggy has calt it some how while she been running..Feels all lose and floppy...Wife takeing her to the vets in the morning....No dowt the vet will charge us 30 pounds and say theres nothing that can be done about it
like last time..As you say he keeps biteing it ware he mite be just licking it!!!
Or...She's chewing at it because hes either bored or it is painful. Check the skin around the claw. If it is sore and irritated!!!
You can have then removed ...But there are people that will agree and disagree as to the age of the dog some will say its best done young as to the nerve endings not forming being youg!!!But best to have a word and see what your Vet says.....