Pete, in my case, the dog ate some of the chicken and carried off the rest, and left only feathers.
It's odd that your dog looses interest in the scent, so I'm gonna suggest something, and don't get mad at this suggestion. Could one (or several) of your own dogs have killed and eaten the chicken? That would account for your scent dog losing interest in the scent. I only thought of this because it happened to me once. I have a chain link pen about 20 feet by 20 feet that is my dogs play area. I only leave them in it when my wife and I are nearby, and never when no one is home. A while ago, one of my chickens flew into the pen, and to our surprise and horror, my extremely gentle St. Bernard pounced on the chicken and killed her immediately. We ran in to try to save the chicken, and it was too late. I think Patti (the St. Bernard) thought she was playing, and didn't realize what would happen. But if we didn't remove the chicken, I wonder if the dogs might not have eaten her. Could something like this have happened at your place? I'm not suggesting that your dogs are chicken killers, but Goldens are so playful, could it have been an accident, and then they ate the carcass?