—Homer, Iliad, Book 23
Sacrificing dogs to appease supernatural forces has been a part of religious traditions as different as those of ancient Greece, where the Spartans slaughtered dogs to ensure victory in battle, and Shang Dynasty China. Some inscribed oracle bones dating to this period (1766-1050 B.C.) mention the rite of ning, which involved dismembering a dog to honor the winds...At the site of Sardis in Turkey, once the capital of the Lydian Empire (680-546 B.C.), excavators uncovered 26 small pits, each containing four pots—a cooking jug, deep cup, shallow bowl, and small pitcher, all used for common meals—along with an iron knife and the bones of a puppy... the burials are the remains of a ritual meal, perhaps dedicated to the Lydian version of the god Hermes. "I do not believe these deposits are evidence of cynophagy [eating dogs], which was not part of the normal ancient Mediterranean diet," he says...In 1937, archaeologists excavating in the Agora, the main marketplace of ancient Athens, made a stunning discovery—a well containing bones from hundreds of people, including approximately 450 newborns, and from more than 100 dogs... the dogs were "most likely sacrificed as part of a purification ritual after a birth...
But dogs weren't just sacrificed in antiquity. In Hungary, a team excavating a site in the medieval town of Kaná just outside Budapest, discovered more than 1,000 dog bones, about 12 percent of all the mammal bones at the site... Daróczi-Szabó believes that the puppies and several other dog burials at the site were intended to ward off evil, a custom that survived in Hungary into the 20th century.
Further details and discussion at the Archaeology Magazine link. This issue of the magazine has a series of article on dogs in archaeology.