Telemachus returns his mom Penelope, and his old nurse, Eurycleia greeted him tearfully. He did not say that his father, Odysseus is back and that he is disguised as a beggar.
Odysseus has been away twenty years and only one creature recognizes. An old hound, lying near, picked up his ears and lifted up his muzzle. This was Argos a puppy trained by Odysseus before he left for Troy.
Argos is treated as rubbish and now he just lays in cow mule and flies eating away at him. He died after he finlly saw Odysssues one last time.