Editor's note: This article has been reviewed and updated for accuracy in 2026. Travelers who want to enjoy a safe and smooth experience should never lose track of the golden rules. Pack the right clothes for the climate you’re traveling to, double check that you’ve got your passport and money with you, write down a few emergency contacts, and… don’t travel with illicit substances or fail to declare the stuff the customs folks want to know about. You, of course, are sensible about all of those things. You still want to know, though — can (drug sniffer) dogs smell weed cartridges? What Can All Dogs Smell? A lot. Research estimates that our canine best friends (or, in this case, perhaps worst enemies) have a powerful sense of smell that’s between 10,000 and 100,000 times stronger than a human’s. That’s both because dogs possess many more scent receptors, and because they have special structures within their noses that amplify even faint smells. It’s no wonder that dogs have been used to sniff out things of interest to law enforcement for ages. Among the things that dogs can easily smell, even if they’re concealed, are: A wide variety of illegal drugs as well as legal controlled substances, such as tobaccoFirearmsMissing peopleBed bugsUSB drivesBelieve it or not, some dogs with specialized training can even detect cancer in people The canine units found in law enforcement agencies receive complex training, and the behavior and personality of each sniffer dog in training is carefully evaluated every step of the wa