I can not resist making some interpretations about your dream, Chuck. You are free to accept or reject them as you wish.
Around Halloween time we are reminded of the fun times we had as children participating in the rituals of the season. We are drawn back into a more innocent time and the inner child within us is awoken. We long for the attention of our parents in creating costumes, taking us out trick-or-treating, making jack o'lanterns, and giving us candy. But when we are grown and out on our own, we have to do all those things for ourselves or for others. Yet, the inner child still wants the attention and playful care from the parent as always. We long for the sense of solace and protection that they provide in a scary situation, even though the scariness is all make believe.
In both of your dreams, there are parent figures who exhibited neglect. In the first one, your parents gave away the cat (and it is implied that they gave away the grandmother to the same location). In the second one, a father neglects his child, who falls into a vat of piranhas. You still need the concern and care of your parents even though you are all grown up and have left the home. Everybody does. However, parents are flawed. I, as a parent, know it's easy to get wrapped up in my own projects and lose touch with my grown children. But they need me, in some ways more than ever.