Police officers using drug dogs ?

Sorry for so long…

In the U.S. if a cop uses a drug dog to go around your car without asking your permission and finds drugs, is that considered unreasonable search and seizure?

What if you already told him he couldn’t search without a warrant and he used the dog anyways?

My brother got pulled over the other night (he’s rough looking, tattoos, has prior drug offenses and all that) and the cop asked to search his truck.

He said “not without a warrant” and this obviously pissed the cop off. Anyways, the cop said, “well, we’re just gonna run the dog around your truck real fast and then you can be on your way.”

The dog didn’t smell anything, and my brother was on his way.

Was this legal for the cop to do? I know you can just ask the cop if you are being arrested or detained and if he says no, you have a legal right to leave after he issues his citation or ticket. Does that coincide with the drug dog business? Is the using of a drug dog considered being detained?

Yeah, it’s legal.

Welp, that article pretty much answers all my questions. Thanks buddy !