sounds like he is getting to much bone. try adding some flesh meat into it, i try to give a good mixture of bone and meat. i also give my pups about half a pint of goats milk each every day. as for veg, well they havnt had any. the only other thing i give mine is brown bread and cod liver oil
oh an i give them tins of sardines and tuna, they are only like 34p for a tin in asda