There are sniffer dogs in all airports and all baggage is X-rayed - anyone suspected of carrying drugs is stopped and searched and then can be handed over to the police or deported

Yes

A drug dog may smell you

Just a few months ago, one of the TSA agents checked my hands for gun shot residue. All luggage is opened these days.

Do they test you for drugs? No.

Do they check you and your luggage for drugs? Yes.

Only if they have reason to suspect you are smuggling drugs

No