A lawsuit filed against the maker of a popular dog food has triggered concerns among California pet owners. Frank Lucido of Discovery Bay, a community in Northern California’s Eastern Contra Costa County, said his 8-year-old bulldog, Dozier, died three weeks after Lucido switched his pet’s diet to Purina’s Beneful dog food. On Feb. 5, Lucido sued Nestle Purina PetCare Company in U.S. District Court in the Northern District of California, alleging the dog food contains propylene glycol, which the suit said is an animal toxin used in automobile antifreeze; and mycotoxins, a group of toxins produced by fungus that occurs...