How we cite our quotes: (Chapter.Paragraph)
Quote #1
Something told me that one of those days she wouldn't come back. We would have to fend for ourselves. […] Mother wouldn't be there to look after me. (1.33)
Early on, our narrator learns that he isn't to trust or rely on other dogs. They are almost always on the lookout for only themselves, and they will abandon another of their species to save themselves.
Quote #2
Mother never [played], though—she had dug herself a hollow behind the railroad ties and spent most of her time just lying there. When I went to see how she was doing, she growled at me as if she didn't know who I was. (2.40)
Mother feels abandoned and alone in the Yard. She is a feral dog, and even though life is harder for her in the wild, she prefers it to being cooped up in the Yard. Our narrator doesn't understand this, and feels that his mother has abandoned him. Both of their feelings are complicated, as they want different things out of life.
Quote #3
Then she turned to look at me, her eyes bright. The message in them was clear: my mother was leaving. (2.45)
Mother is leaving, but is she actually asking the dog to come with her here? It doesn't seem like she has had much of a desire to look after him after they were captured. Why would she start caring now?