Thank you for your suggestion on the sweet potato. We give both our dogs sweet potato almost everyday for 7 months now and it has helped with the smell, it is especially great for their "dog breathe". We prick the sweet potato with a fork and put in the microwave for 5-7 minutes. Everything the microwave comes on, our dogs sit and wait for their sweet potato.
I tried the sweet potato and It works, plus my dog loves it.
My newfie has always had goopy ears and a slight doggy odor about her. At her last chiropractic visit, the chiropractor said that for some reason the big fluffy dogs are more prone to doggy odor and to give her 1/2 of a sweet potato every other day. She said just fix the sweet potato the way that I normally would and give it to her. So, I baked it in the microwave (poke some holes all around, nuke on high for 10 minutes, when done, immediately wrap in aluminum foil and let sit for at least 5 minutes), mashed it up with a little butter and gave it to her. Almost immediately I noticed a big difference - no more doggy odor and BONUS her normally goopy ears were clear and dry!!! Now she gets her sweet potato as prescribed - and they don't cost a fortune.