We have 2 7month old bordercollie/lab mixes that have been around our livestock since we have got them and had no problem. Wednesday they defeathered a turkey that has been known to attack and was heading to the block anyway so I talked myself into thinking the tom attacked them first. today they went after a young goat that I almost didn't get to in time. I talked to our large animal vet and he said some dogs have that killer instinct and as hard as it is that he recommends putting them down. we have 2 children and one on the way so their safety is important. I hate the idea of putting them down but this behavior can't be allowed. does anyone have any experience with this or any suggestions?