As in many cultures Zoroastrians consider corpses as foci of pollution. Corpses are unclean and dangerous since they are afflicted by the demon of dead matter. As soon as the dying person loses consciousness, the demon of dead matter arrives from the north in the form of a fly and attacks the body. To counteract her influence, a corpse must be exposed to the gaze of a dog or a bird of prey before it is left exposed outside in the funerary tower. The dog’s presence forms an essential part of several Zoroastrian purification rituals. In this article we shall discuss two of these rituals: the sagdīd and the Baršnūm.