Arwen has the Chow Chow mentality– you threw it? You go get it. She would occasionally get something just to annoy the Rottie, occasionally in the house to stop Cara.
Cara-- fetching fool.
hopefully Dex is just teething. I worked very hard to keep toy-drive in Zest as it can make training easier and more fun. And she still often gets a treat for retrieving or tugging her toys.