
Go back to your vet and ask for the dog to be tested for thyroids. This as one of the first symptoms grandperents boxers got, it then went to alot more hair loss and then his nose drying up and him becoming VERY lefargic, went to two vet practises and they didn't have a clue, went to another vet and she saw him and said thyroids, had him tested and he was, now being treated after too many years but he has improved alot!!!
If its not thyroids then possibly evening primrose oil from Hollands and Barrets should help coat grow back.
Rox