bad smell

Question
i live in Scotland and have a 13 month old cocker spaniel who has a really bad smell like bad smelling feet. we have had him check by the vet and groomers and have been given special shampoo called virbac .the groomers have cut and trimmed all his coat and paws but still the same smell. when you smell his coat there is no smell from his him it is more like a lingering odor.After he has been washed he is fine for couple of days then the same smell come back.we have changed his food from bakers dry food to pedigree wet food two days ago hoping this will help but if you have any other suggestions on a different food or shampoo it would be much appreciated

Answer
I think he's got some yeast overload.  Bath him every second day for a week - then every 3rd day, etc.  You'll find out what he needs for maintenance.

Get some Nizoral shampoo if available.  

After his final rinse (and rinse VERY well) - give him a last rinse in half water/half white vinegar.

Initially you really do need to get on the bathing and the rinse.