Why does Paulsen regard Ike as a friend, not as a pet?

Ike was like a best friend to Paulsen.... he was his companion, they enjoyed doing the same things.He says that Ike was "a great barrel-chested black Labrador that became one of my best friends I've ever had and was in all ways an equal." At the time, "I lived and breathed to hunt, to fish." Note, Paulsen was not a good aim, and someone trained Ike to be a fine hunting dog, one who knows good hunting when he sees it. When Paulsen missed a shot, "he would watch the duck fly away, turn to me and give me a look of... uncompromising pity and scorn."

Paulsen was saddened when Ike stopped meeting him after school, but years later Paulsen learned that Ike's master had returned wheelchair-bound from the Korean War, and Ike stayed with him after his return. "That was why Ike had not come back. He had another job."