My dog's farts smell like hell with retort...why?

We feed her the best dry food (Natural Balance, Innova, Solid Gold, et. al.), excercise her daily, extremely minimal table food (and never gy stuff like cauliflower, beans, McDonalds or mexican food) but yet she rips wind non-stop and it clears the room. She's a bigger dog (bloodhound) but we have a pretty roomy house. She's healthy as a horse, but damn. I can't continue to be relegated to locking myself in the closet while the dog is blowing rotten funk all over creation like the County Mosquito Fogger Truck. She's been on antibiotics for other problems like ear infections and you would think that would kill the stink demons that are apparently thriving in m colonies in her lower bowels, but no luck so far. I'm about ready to feed her charcoal and strap a carbon absorption unit to her rectum. Any suggestions?