are there any toy drug dogs?

I have seen a Yorkie put into service with the DEA

The inner nose is compiled with olfactory receptor cells to process scents. Dogs with longer muzzles have more olfactory receptor cells than dogs with short muzzles. In example, humans only have 5 million olfactory receptor cells; where as a German Shepherd Dog has 220 million! A dachshund has 125 million, and a fox terrier has 147 million. So different dogs have different scenting abilities, but they all out rank us humans. Another reason dogs smell so well is that at the end of each of these olfactory receptor cells, there are cilia. The cilia are tiny hairs coated in mucous and help to trap scents with in the nose. Humans have about 6 to 8 cilia at the end of each olfactory cell, but dogs have 100 to 150. Each of the olfactory receptor cells connect to nerves that lead to the olfactory lobe in the brain. In a dog’s brain, this lobe is the size of a large walnut, where as in a human it is the size of a pea. Detection work is primarily done by Labs, Golden Retrievers, GSD, Border Collies and Belgians. I train detection dogs and I’ve seen many other breeds be successful mostly in search and rescue. It also comes down to the intelligence, drive and trainability of the dogs. Local law enforcement needs dogs that can also do aggression/bite work. The feds mostly use Labs, Golden’s and Border collies.

Probably a few. My Min Pin is excellent at scent discrimination and tracking, and my Boston Terrier is passable at it, though they are not trained to detect drugs specifically. While they aren't traditionally used for the work, there's plenty with the aptitude to do the job.

I know a guy with a pet raccoon that's addicted to cocaine if that'll help you out?