Dogs have evolved with humans, and therefore are very, very keen on what works with their two-legged companions. Not in an evil, manipulative way but just in ways that are effective.
For example, many dogs have learned that the way to get their humans to be fun and engaging is to sag. I do not mean literally, of course, but rather a general sag of attitude and attention. I imagine the conversation at Dog Class goes like this:
Dog 1: How do you get your human to play so much and to hand over all those great cookies?!
Dog 2: Easy Peasy Liver Squeezy. You can head off to sniff — that works well. Or you can just stop looking like you care — you know, look around, don’t make eye contact, look all sad.
Dog 1: Wait — what?! Are you serious???!!!
Dog 2: Yep. Just act disinterested and the toys and cookies will rain down on you. Humans are so trainable!
Oh Dear.
We train dogs to disengage when we provide rewards for disengagement behavior.
That said, sometimes the dog disengages because of external factors, including handler anxiety, and even internal-to-the-dog factors that we may not understand. Nothing is really black-and-white, except maybe zebras.
We should, however, be aware that we may have inadvertently trained our dog to disengage, and we should definitely stop reinforcing disengaged behavior.
Personally, I do not believe in adding anything mean when a dog disengages. Instead, I am a fan of training what I want to see in the future — and that does not include a disengaged dog.
Unless we are intentionally using food or toys to lure during a training phase, cookies and play should happen ONLY when we have desired behavior. And even when luring, one should not release the reward when the dog is disinterested!
So what to do if we have failed to be more interesting than dirt? Here are some options — I would save #3 and use only as really needed.
Wait. Say nothing and see if the dog will engage. If she does, have a verbal praise party and ask for a couple of easy behaviors before the reward. You do not want to set up: sniff, look at human, get cookie. How does the dog understand that the sniff is not actually part of the behavior chain?
Walk away and do as above if the dog finds you.
End the train session — even for just a few minutes.
But I need to say this — prevention is better than intervention.
If a dog has a disengagement issue, the human needs to work harder to keep the dog engaged by being more interesting, consistently rewarding engaged behavior with play and treats, and quit training sessions before the dog has a chance to disengage.
Happy Training!