As I understand it, the desired behavior is for the dog to maintain her gaze and focus in the direction of the last bird thrown until either she is sent, or until she is specifically cued to turn in a new direction. For Field Trials and events based on Field Trials, that cue comes from the handler. For Hunt Tests, the handler is not permitted to explicitly communicate with the dog while the birds are being thrown, so the cue to turn is the duck-call and/or gunshot from the new direction.
I'll mention in passing a couple of things I've heard from traditional trainers:
- Once the dog understands the concept of multiples (doubles, triples, quads), run 90% singles. Besides helping solve head-swinging, that is said to be advantageous to the dog's marking ability, as well. I've seen a few people who follow this practice with advanced dogs, but not many.
- If the dog swings her head during training when you were planning to run her on a multiple, don't call for the next bird. Instead, send her to the one she took her eyes off of.
At the Senior Hunt Test both dogs ran on Saturday (Lumi had a call-back to water, neither Lumi nor Laddie qualified), the handlers were required to carry an unloaded shotgun to the startline on both the land and water series. The only requirement was that you carry it, but many pointed the barrel at the birds being thrown as well. I've never done that before because I was afraid it would disrupt our line mechanics, but on Saturday I decided to try it. At the same time, I watched my dogs' heads.
I was pleased to see that with the barrel of the shotgun pointed toward the fall, both dogs maintained their gazes. Laddie doesn't have a head-swinging problem anyway, but it was great to see Lumi exhibit that same focus in both series.
I think that in the future I'll use some sort of imitation shotgun — perhaps a lining pole if an empty shotgun isn't available — when we run multiples in practice. Hopefully, that will support development of a non-head-swinging habit. And in the occasional event in the future where a gun isn't carried to the line, hopefully by then the habit of holding the gaze will be well-enough formed that it won't matter that no gun barrel is assisting that particular time.