Allergies: My French Bulldog, 26 lbs, was given Ketoconazole for a large sore on her muzzle several years ago, like a cold sore. I stopped using it as soon as she became sick. I then used lemon balm ointment from Whole Foods, which my daughter uses for cold sores. The lemon balm works wonderfully. I also wash my dog down weekly with a little vinegar in water (no soap) and wash her face daily in diluted hydrogen peroxide.
She is now 5 years old and extremely healthy, no more sores, no itching and scratching in the summer. Also, she no longer gets shots or vaccinations.