Hundreds of drug-detection dogs are taking early retirement, their jobs disappearing as marijuana legalization makes their skill set obsolete. It’s not the dogs’ fault; the blame lies with human myopia.

Dogs can be taught to identify pretty much any scent, even scents that humans cannot detect. The dogs who sniff out cancer or flag diabetics whose blood sugar is dropping, for example, are responding to scents that humans cannot smell.
Dogs can also be taught to reliably distinguish scents and alert to more than one scent. And they can of course be taught to respond to each scent with a unique behavior — a bark, sitting, lying down, spinning in a circle. It really doesn’t matter what; the dog can learn it.
But the humans. Oh, the humans.
There are the trainers who take the “easy” path of teaching their canine pupils to give the same alert to any contraband. Easier to teach. Easier for the handler to remember. But it makes the dog’s skills useless when you no longer want her to alert to marijuana.
There are the humans — trainers, handlers, lawyers, judges — who do not believe that dogs can discriminate the scent of meth from the scent of marijuana. Or who do not believe that dogs can reliably signal which one they’ve detected.
For these reasons, many drug-detection dogs who’ve served faithfully and honorably are being pushed out of their jobs. In places where marijuana is now legal, basing an arrest on the dog’s say-so is too risky. Defendants can argue that the dog alerted to a legal substance.
Many detection-dog trainers are have already stated training dogs on other forms of contraband but not marijuana. And new recruits, who’ve graduated with this newfangled curriculum, are stepping up to take the retiring dogs’ jobs. Even so, there are sure to be younger dogs caught unprepared as the job market shifts, new grads whose skills are outdated before they’ve had a chance to shine. The thousands of humans forced to adjust when their jobs vanished will understand how tough this can be.
The retirees’ future is not bleak, however. Most of these dogs are headed into a cushier retirement than many people can look forward to. Many of them have years of experience under their vests and deserve to enjoy their golden years. And who knows? Some may pivot to new careers. I hear there’s growing demand for conservation dogs…