Dog odor

Question
Am looking after a 10 year old chocolate brown lab. She has returned to me with a very strong odor.(like a doggi smell but much stronger) Owner recently had anal glands squeezed.  Lab has swum a lot in river. owner has bathed her but smell persists.  Owner changed food to Iams.  I fed her Hill's adult light. Dog seems well and active. a Strong smell only started 2 months ago.  Am puzzled, can you advise please.

Answer
Can you track the smell down to something like ears or feet?  It's also possible if the dog has a thick coat, to have a fungus infection on the skin.  

If she has been bathed and smells bad still, I might have a vet look at it to rule out any medical conditions.