I was looking after a mates 3 working dogs over Xmas, he rang me on Tues arvo to tell me that morning he had just mustered a paddock where he works and it was their 1st job since the Xmas break and he was very pleased with how they had worked then on the way back the dogs took off after a big kangaroo and didn't come back when he called. They chased it across another paddock and ended up with the roo in a dam up to its neck, his most promising young dog Xena swam out to it and the roo just reached out with its front legs and pulled the dog under and drowned it. It happens more than you think.
Ken