Well, Pedigree isn't very good food but that may have nothing to do with it. Are you changing foods? If so, did you do so gradually? It's possible of course that something in one or both foods disagrees with her (i.e. the corn in Pedigree).
It might be a good idea to put her on a simple, bland diet of something such as boiled chicken and rice for a few days to see if that helps.
It might be a good idea to put her on a simple, bland diet of something such as boiled chicken and rice for a few days to see if that helps.