A year ago my then 5 year old black lab started itching and chewing himself. Vet ruled out fleas, but told us to try changing his food which we did, have tried various shampoos which were then recommended, and he was given a cone to wear to stop him chewing himself (a year later we're on cone #3), as soon as it's removed he's chewing himself or scratching. Vet seems to have run out of ideas so we have continued shampooing him every week and brushing him every day but he is almost bald on his back. We've tried antihistamines, salmon oil in his food, brushing, bathing him but the vet thinks it's become a habit with him. Any ideas? Don't think he wants to be wearing a cone indoors for the rest of his life either.