SunDance,
I train my dogs on the command "SHAKE", but always in conjunction with them coming out of the water. I think it would be tough to teach otherwise because it is not something they do regularly otherwise. Timing is critical and I watch for them to execute the behavior after exiting the water and keep my self in front of them so that they can see me. Initially I execute a gestural cue along with the verbal command "SHAKE" as they do the behavior and mark the behavior with a "GOOD DOG" as they do it. As they become more proficient, I time my gestural cue and verbal command to precede their shake as I watch for their physical cues to me that they are about to do so. Again the behavior desired is verbally marked with a "GOOD DOG" and additionally a high value reward can be delivered as timed with successful demonstration of the desired behavior by the dog to reinforce that behavior. Many repetitions are required to entrench the desired behavior and I believe that a dog that gets wet frequently lends itself to learning this behavior with a much higher degree of success. My dogs are working Labs and they are worked in the water at a very high level of frequency both whilst training, hunt testing, and hunting, that giving us lots of opportunity to shape the desired behavior. For myself, I do not want my dogs stopping to shake at the water's edge to shake as they exit from a pond. Too often, dogs will drop a bird to shake off water while making a retrieve from a body of water if not trained to do otherwise. I use specific training methods to teach a dog to shake only after they have made delivery of the bird or training bumper to hand, and only after commanded to do so. My dogs will sit to make delivery and I will keep them at sit and move just out of immediate range from their (spray zone) before giving them the gesture and command to "SHAKE", THIS ALLOWING THE DOG TO SHED EXCESS WATER WITHOUT GETTING ME DRENCHED.😁
Cheers,
Mike 🍀🇮🇪🇺🇸