Despite only being trained to detect the "big six" (cannabis, cocaine, fentanyl, heroin, methamphetamine, and MDMA) drug dogs are somehow magically able to provide probable cause to search packages that their chud handlers think might have abortion medication. The cops explain this by saying that abortion drugs are commonly packaged around narcotics.
how do they mail the dog? I don't understand, isn't that wildly impractical?
I think they are talking about dogs that will be stationed and sniffing in the places where mail has to pass through to be sent to the correct destination.
Right. The specific scenario they're concerned about is someone sending in a "tip" that a particular person or organization is mailing out abortion medication, then the cops intercepting all the mail from that person or organization and having a dog alert on it so they can get a warrant to open it and seize the contents. This works even if the dogs aren't trained to sniff out any of those drugs, because handlers can "cue" the dog to alert on anything they want to (deliberately or not). This is also how lots of K9 traffic stops work.