> she is on one by James Well Beloved, fish and rice.
I don't remember it making mine gassy (but they weren't on their fish and rice) but it was too 'powdery' for mine and I stopped using that. Usually it's cereal based food that tends to make dogs gassy - something I have to be very careful about as mine is a breed prone to GDV (Bloat). Remember rice is a cereal. You might look for a fish and potato food instead. I use Arden Grange's Sensitive, or sometimes their Salmon and Rice which is slightly less expensive.
If she's gulping her food down, try using one of the slow-down dishes?