In Homer's Odyssey, the hero, Odysseus, has a dog named Argos. We are told by Homer that Argos would frequently accompany his master on hunting trips and guard the palace of Ithaca when Odysseus was away. Argos was an intensely loyal companion, and it is noted that Odysseus was exceptionally fond of the dog, whom he regarded as a confidant and friend.
When Odysseus departed his home to fight in the Trojan War, Argos remained at the palace. Odysseus bid farewell to his family, and then departed for what would become the longest and most savage war in his culture's history.
After the war ended, Odysseus found himself at the mercy of Poseidon, wrathful god of the ocean, and cast far from his home and family. Odysseus found himself shipwrecked and stranded far from Ithaca. He had spend ten years at war, and the next ten years on an epic journey to return home.
Upon his return, Odysseus was disguised as a beggar by the goddess Athena, in order to not arouse the suspicions of his wife's suitors, whom had taken up residence in his palace and plotted to murder him upon his return. When Odysseus made it to the palace, dressed in peasant's rags, he beheld a most unusual sight: an aged and ragged hound, sat atop a pile of its own filth, more dead than alive and with barely the strength to even breathe. Odysseus realised that this was his faithful dog, Argos, and was moved to tears by the sight.
We are told by Homer that Argos, with a dog's keen nose, saw through Odysseus's disguise and recognised the scent of his beloved master. Argos, for the first time in twenty years, held his ears aloft and wagged his tail.
He then drew his last breath and died.
Sad yet?