Aww, I feel sorry that you still got late with this. It's a wonderful cartoon! What matters most is how authentic it is. Everyone can relate to this. Everyone at least had a mom at one point. The music was so beautiful.
I just got chills watching this! Even though they're all dogs, this was so realistic. The animation is just wonderful. We all get to see ourselves growing up if we reach this age. Yeah, I don't want to sound morbid by suggesting many people die young. Happy belated Mother's Day to you too, dude!