"The U.S. Supreme Court ruled Tuesday that police may not detain a traffic violator longer than needed so as to allow police time to conduct a dog sniff for drugs."...
I think the same thought process could reasonably be applied to other fishing expediotions conducted in conjunction with a minor infracton stop. So STFU, take your ticket, & ask if you are free to go. Then do so...http://www.npr.org/2015/04/21/401282284/supreme-court-police-may-not-detain-traffic-violators-longer-than-necessary
Learn it, say it respectfully, act accordingly. Remind them you do not consent to searches.
As for the accuracy of a dog's sniff, that's an issue I really have a problem with but it's a long road to overcome. Too much chance for the handler to trigger to false positive, and there's no way to challenge the witness: "Dog, you indicated you smelled the odor of illegal narcotics in my client's car, is this true?" "Woof!"
They need to start publishing the accuracy, and their training and "calibration" records just like is available for other law enforcement tools. Dogs are not infallible, yet are treated as sacred. Frustrating to me as a citizen.
I have had fairly extensive experience with the use of dogs as detectors in other industries. Dogs false alert a lot and for no plausible reason. Yes---they get it right a lot---but they aren't anywhere near 90% accurate in their assessments !!