Itzcuintli, the dog, carries one of the tonalpohualli's most concrete ritual associations: the dog was buried alongside the dead to carry them over the nine rivers of Mictlan, the underworld, and the day sign binds the living directly to that same underworld journey every soul was expected to face. Despite this close connection to death's passage, the sign's auguries themselves read warm: Sahagun records the dog days as generous and fortunate, days of hospitality and of those who give feasts, a favourable reading that draws on the dog's equally well attested role as a loyal companion in life rather than only its funerary duty. This combination, a sign bound to death's crossing yet read as generous and hospitable in ordinary life, reflects a broader pattern in Nahua thought that did not treat mortality as something to be read only darkly, since the dog's guidance made death survivable in the same way Cuetzpalin's regrowth made injury survivable elsewhere in the count.
Itzcuintli opens its own trecena, Trecena 14, where the same generous, feast giving character governs the whole thirteen day week under the patronage of Xipe Totec, the flayed lord of spring renewal. Mictlantecuhtli's own consort Mictecacihuatl shared his rule over the dead the dog was buried to guide, and Sahagun's account of the funerary provisions bound with a body, food, cloth and the dog itself, treated the whole underworld journey as a real logistical undertaking rather than a purely symbolic one.