Thanks for replying Joy. Yes it's the fungal skin complaint that is the problem. He's an old dog (though strong and fit) and he's had the problem for many years so I guess it is too much to expect UT to perform a miracle over night.
HOWEVER he has also had an ear problem for years and his ears have completely cleared up (they are even a different colour inside) so UT is doing something! I wasn't putting in his ears just giving it mixed with chicken stock.