Dog in Hindu society is considered an inauspicious animal. In North India it is not a very common sight to see a dog in houses in general. An exception I saw in Kachchh, when I was in Anjaar, that dogs were welcomed there in the houses, sometimes even in the kitchen. The women there fed them and after eating the dogs went away.You will be surprised to know several descriptions of dog in our scriptures, how and where, let us see ---
(1) Dog in Ved
Rig Ved Rishi have mentioned Dogs in at least 3-4 Mantra in Rig Ved, however, the stories are not there, because Upanishad doesn't contain text related to popular Indra, Sinhaasan and Devtaa and Daitya, God or Demon type stories, their subject is only Brahm and Aatmaa.
(2) Dog in Raamaayan
In the Uttar Kaand of Vaalmeeki Raamaayan, (V-Raamaayan, 7/24 Sarg 24) there is reference to a complaint made by a dog against a Braahman who had hurt it without any reason. Raam summons the Braahman concerned and admonishes him. He then asked the dog what punishment should be given to the Braahman, and the dog says "Make him a Kulapati (a kind of University Vice Chancellor) Kaalanjar Pradesh for I was such a Kulapati in its previous birth and had hurt many students, that is why I took birth as a dog. When he would be the Kulapati, he will also behave in the same way, and will be born as a dog in his next life." Raam laughed and punished the Braahman as the dog prescribed.
(3) Dog in Mahaabhaarat - Yudhishthir's Dog
--Yudhishthir had a dog with him when he was going to Swarg (in Swargaarohan Parv of Mahaabhaarat). He did not leave this dog in spite of Indra's threat that he would not be able to go to Swarg because the dogs were allowed in Swarg. When he did not get ready to go to Swarg at any cost leaving the dog behind,, the dog showed his real form and blessed him. In reality that dog was the father of Yudhishthir - Dharm Raaj himself, although he did not now it. (MBH, G-7-Postwar/34)
-- Because of being inauspicious animal, once Raajaa Janamejaya was doing a Yagya along with his brothers, that a dog came there and just stood there. Janamejaya's brothers considering him inauspicious pushed him back. By chance they did not know who that dog was. So after being pushed away that dog went to his mother and when his mother saw him beaten badly, she asked him what had happened to him. He told the whole story that he was just standing near the Yagyashaalaa that Raajaa Janamejaya's brothers beat him and pushed him away, although he did not do anything to annoy them. In fact he was the son of Indra's bitch Saramaa, so Saramaa came to Janamejaya's Yagyashaalaa and asked them as why did they beat her son without any reason. They could not reply, so she cursed the King - An evil will fall on you when you will least expect it."Raajaa Janamejaya came back after the sacrifice and had to look for somebody who could neutralize its effect. (MBH, G-0-Prolog/4)
(4) Indra's Dog
--Indra himself has a bitch named Saramaa whose son was abused by Janamejaya's brothers when he was doing a Yagya. At that Saramaa cursed Janamejaya that his Yagya will come to stop in between by a Rishi - the story is given in under the heading - "Dog in Mahaabhaarat" above.
--Saramaa is said to have pursued and recovered the cows stolen by the Panai Asur and hidden in the nether world of Paataal.
(5) Yam Raaj's Dog
Yam Raaj, the God of death is believed to have two ferocious dogs Sarameyas (described as the off springs of Indra's dog). Both of these dogs have four eyes each and they guard the road to Yam Lok. Yam himself took the form of a dog, while guiding Yudhishthir to Swarg Lok, see below. [MBH, G-7-Postwar/34]
(6) Kaal Bhairav's Dog
The vehicle of Kaalbhairav (a fierce firm of Shiv Jee) is a dog.
(7) Bhagavaan Dattaatreya's Dogs
Dattaatreya's picture can always be seen with four dogs following him.
(8) Shankaraachaarya and Dogs
Once when Aadi Shankar was in Kaashee, while returning after a bath in Gangaa River, he was confronted by a Chaandaal with 4 dogs. The Chaandaal was none other than Vishwanaath, the presiding deity of Kaashee, Himself, in disguise. The 4 dogs were the 4 Ved. Not recognizing this, Aadi Shankar requested the Chaandaal and the 4 dogs to move away from his path, whence the Chaandaal questioned that - "Who is to move away - their body or Aatmaa? If Aatmaa is indeed the same amongst every one - a learned scholar, a low-caste person and the dogs, why should Aadi Shankar ask them to move? If Shankar was referring to the body, then by Shankar's own admission, this body was temporary and one should not identify oneself with the body. On this count also, there wasn't any difference between the two of them." Gifted with a razor-sharp intelligence, it did not take long for Shankar to realize his folly and that the Lord Himself was before him in the form of Chaandaal and dogs. He immediately burst out with a philosopher's delight - Maneesh Panchakam a five-stanza exposition of the body-soul concept.
(9) Dog's Reference Elsewhere
Five Characteristics of a Student
Kaak cheshtaa, bako dhyaanam, shwaan nidraa, alpahaaree,
griha Tyaagee, vidyaarthee panch lakshanam"
Roughly translated - the five indications of a good student are ---
(1) perseverance of a crow,
(2) concentration of a crane,
(3) light sleeper like a dog,
(4) light eater,
(5) staying away from home (means noise, emotions).
Read also Dog or God, and Man and God