What functions as a symbol in this excerpt?

Treated as rubbish now, he lay at last

upon a mass of dung before the gates-

manure of mules and cows, piled there until

fieldhands could spread it on the king's estate.

Abandoned there, and half destroyed with flies,

old Argus lay.

a mule

the king

Odysseus

Argus

Argus became slave, as his master Odysseus was gone. He was neglected and maltreated but despite of these, he remain hopeful that he will see his master before he took his last breath. Moreover, the faithfulness and loyalty of the dog symbolizes the love and the simple relationship of Odysseus and Argus.