How very sad. What a beautiful roo . Many times it is the owner's dog or cat that kills their chickens. I'm a dog lover since birth (now 70) and would NEVER want to have a dog or cat loose among chickens, ducks, etc. Sometimes the pet is just waiting for the right opportunity.
Once they have made a kill, I would NEVER trust them again.
Once they have made a kill, I would NEVER trust them again.