I don't know much about kids since i'm still young myself, but I do remember those charts in school with your name. You would get a gold star if you completed an activity. One of my teachers used these charts for the accomplishments we made while learning times tables. You could make a chart like this and assign each child to a different activity like "feed the dog" each time they do it, give them a new sticker. I think that soon they'll learn that taking care of a pet is fun and they'll want to do these chores.