Cedar bedding is potentially toxic to any animal, from hamsters and rats, to dogs and horses. It really shouldn't be used, and is only in the store to sell to inexperienced rodent owners who do not understand the dangers, so they buy the cheapest option. There are much safer alternatives out there that are equally as affordable for people who aren't willing to put the extra money out there for better bedding.
Cedar, treated or untreated, has strong natural chemicals in it that controls odors for a longer period of time than the paper based products, enticing budget-conscious consumers. However, these same chemicals (including the odor they produce) pose a serious threat to the health of pets, ranging from lung to liver damage.
Selling these products in a pet store, especially in the rodent section, with rodents on the labels, is pushing it's use to misinformed consumers. By selling this product in the Pets' market, Pet Stores are responsible for the cruelty that those animals endure by living in cedar bedding.