http://tenets.parsizoroastrianism.com/dog33.html
Dogs are given utmost importance in our religion. Sarosh Yasht Hadokht (karda 7), mentions "Pashush-harun" dog and reveals that just as this "dog" protects the other innocent, good creatures of Spenta Mainyu, Sarosh Yazata, similarly, protects us. Here, "dog" is compared to Sarosh Yazata! This "dog" therefore, is not just a dog in animal form, but its name "Pashush-harun" indicates that it is a mystic reference to "pasu" (life-atoms, seeds of consciousness); and "harun" or "haurva" indicates perfection and union with the Divine. This "dog", therefore, leads one to Sarosh Yazata who is Manthra Incarnate, Keeper of the Mysteries, Protector of Souls in Both the Worlds!
Again, in the Vendidad, several references are given related to "dogs" in Fargard 5, specifically in Fargards 13 and 14. Various different kinds of "dogs" are described. Fargard 13.9 even declares that a soul cannot pass the Chinvat Bridge and go to heaven without passing the "dog" who guards the Gates of Heaven! This indicates that there is an astronomical reference also connected to "dogs". For example, in astronomy, various "animals" refer to constellations, etc. Sirius is the "Dog Star" and in mythology, it guards the gates to heaven. In Greek mythology too, "dog" Cerberes is the guardian of heaven. Another point to note is that Sarosh Yazata is also the Chieftain who is charge of heaven. We turn over the protection of the soul in the other world under the care of Sarosh Yazata! Hence, what is stated in Hadokht Yasht, is echoed in this Fargard of Vendidad. Further, it is stated that when a dog barks during the Ushahin gah, evil is destroyed. Once again, there is a parallel with Sarosh Yazata. Sarosh Yazata is the protector at night; dog protects at night too. Mystically, darkness is spiritual ignorance. Sarosh is the Voice of Conscience; the Seat of Divinity, in the human constitution. A dog's bark is likened to the "naad" or sound of Sarosh Yazata who protects us from evil (mostly arising out of ignorance or spiritual darkness)!
The entire Fargard 13 is dedicated to "dogs". This also lends support to the 19th chapter of Bundahis, where again, animals, and dogs in particular, are mentioned. Vendidad also mentions in particular the shepherd's dog, water dog, guard dog, etc. and admonishes that grave consequences befall those who kill dogs. Meaning, besides killing a creature of the good creation of Ahura Mazda, those who kill "dogs", kill their conscience and spirituality!
During the funeral ceremony, dog is brought in to view the corpse. This is called the ritual of "sagdid". It has many purposes. The dog is able to detect suspended animation. If a person is not really dead, but in coma, the dog detects this. The dog is also able to kill the druj-e nashush or microbes, etc. generated by the decomposition taking place within the corpse. This, the dog is able to accomplish because of the fact that its eyes give out certain magnetic currents (we all discharge magnetic currents through eyes, finger tips, head), that are so powerful, they destroy the harmful microbes from the surrounding area. Yet, another reason to let a dog view the corpse is because the soul is given in the protection of Sarosh Yazata and "dog" is this Yazata's Earthly Representative! It allegorically shows the road to the other world, through the Chinvat, to the departed soul.
Sincerely,
Pervin J. Mistry.