I have researched on the Internet so much on fishy breath for dogs. My sheltie has fishy breath but doesn't have fish in his food, I don't think it's his anal glands which seems to be number two and I brush his teeth so doubt it's his breath. He's so healthy, but I guess now I should ask the vet. I don't want to panic since I had a previous 3 yr old with a cancerous chest mass but wondered if this was normal.