Is just the one eye swelled? No other facial swelling? None of my dogs with food allergies have ever had facial swelling. Not saying it couldn't be the food, just that I've not had that happen with any of my guys. I'd first think possible bug bite since the rest of the face isn't showing any swelling. Has the eye swelling gone down today? The belly rash could also be the food or environmental. It's so tough to tell. Frustrating when you have a sensitive dog, isn't it? I'm sorry, but I forgot what food you switched to. Acana, I think, but what protein source is it? Any change in detergent or carpet treatments?