A doggie bag is a container which is used to package leftover food at restaurants. The term is a reference to the idea that many people like to bring home scrap bones and other food for their canine friends. In lieu of “doggie bag,” people may prefer to say “to-go bag” or simply “box.” The term is probably most widely used in the United States; this can perhaps be attributed to the fact that there are around 53 million dogs in the United States, according to the American Veterinary Medical Association.
At an eat-in restaurant, people can end up with leftovers due to generous portions or deliberate over-ordering. Many people are reluctant to waste food, especially if they enjoy their meals, so most eat-in establishments provide boxes for packaging leftovers at the end of the meal. It is not uncommon to collect to-go or takeaway boxes in a bag so that customers can easily manage them, and in more homey, casual restaurants, this bag is often called a “doggie bag.”
Doggie bags are also convenient for people who practice replating, the gifting of wholesome leftovers to people in need such as the homeless. Doggie bags can help keep food organized and warm, and people can write short messages on them so that homeless people know that the contents are safe to eat.
The implication of a doggie bag is that the owner plans on feeding the contents to his or her dog. In the case of scrap material like bones, the contents of doggie bags often do end up with canine friends, but true leftovers are usually consumed by humans. Since feeding leftovers can destabilize a dog's diet or interrupt training regimens, pet owners should actually try to avoid indulging their dogs with leftovers. In some cases, common human ingredients can even make dogs very sick, and dogs generally do not enjoy heavily spiced foods.
To-go restaurants rarely call their bags “doggie bags,” since they assume that their food will be eaten by the humans who ordered it, and not their pets. Some restaurants also provide special to-go meals just for pets. This practice is especially common at traditional French restaurants, as dog owners in France often bring their pets with them to eat, and chefs in training are expected to prepare food for the dogs. Meals formulated just for pets generally take the dietary needs of the animals into account, and this sort of doggie bag can be a nice treat for a furry friend.