Australian Cattle Dog Cross Gets Small Crunchy Bites

What kind of dog we have: We are owned by an Australian Cattle Dog cross. Age: 6 1/2 years old, spayed female Brand of Dog Food: Pedigree, Adult formula, Small Crunchy Bites. Recc. by Vet? No- vet said she was in fantastic health, and to keep feeding what we are currently using Purchase from: Wal-Mart or Sam's Club, because we are usually there already, and it is lower priced there than at pet-oriented stores.