I dreamed that I was at a ranch with my friend. He and I were both playing with a dog on the grass. However, this odg was a robot; he was completely electronic. There were also other kids at the ranch, who were playing with a gigantic dog (this one real), and each person had a score, as if they were playing some sort of game. I went to participate in the game, and lost quickly because the dog bit me. I was in last place. I asked the dog why he bit me and he put his arm around me, as if a person, and said it was because I was older than he was. As a result, I lost the game and the dream ended.
I would guess that you have a dog in real life. Perhaps the fact that the first dog was electronic would have something to do with you not wanting the dog to go away or pass away. It seems to me that you miss you dog because you are either away from home and haven't seen him for a while, or because he has passed away.