When Indra comes to take Yuddhisthira to Swarga, the latter refuses to go without the dog who has been accompanying him all this while:
"Yudhishthira said, ‘O thou of a 1,000 eyes. O thou that art of righteous behavior, it is exceedingly difficult for one that is of righteous behavior to perpetrate an act that is unrighteous. I do not desire that union with prosperity for which I shall have to cast off one that is devoted to me.’
This is when Indra replies:
"Indra said, ‘There is no place in Heaven for persons with dogs. Besides, the Krodhavasas take away all the merits of such persons. Reflecting on this, act, O king Yudhishthira the just. Do thou abandon this dog. There is no cruelty in this.’
My question is - What reason do the Krodhavasas (Asurik sons of Kashyap's wife Krodhavasa) have for disliking dogs or people with dogs? Especially since Yama himself has two dogs that guard his abode?