Legal marijuana is in the air across California, but local and state law enforcement agencies say they won’t retire their pot-sniffing narcotics dogs anytime soon, reports the San Francisco Chronicle.

At first, it might seem like California’s legalization of recreational pot would render canine units’ weed-sensitive noses obsolete. Indeed, some dogs are being pulled from routine patrols, and new ones are sometimes not trained on pot. But police agencies say their drug-trained dogs still have plenty of value, especially when it comes to taking down large-scale drug operations.

"While laws regarding marijuana have changed, certain activities are still considered crimes," said Giselle Talkoff, spokeswoman for the San Francisco Police Department. "Laws and regulations still govern sales, possession and transport, (and) there are times when the illegal possession of marijuana can coincide with other crimes."

Most of California’s drug-trained police dogs go through an intensive training program where they learn to bark or sit when they smell heroin, cocaine, methamphetamine or marijuana. The California Highway Patrol, which employs 42 drug-sniffing dogs, trains them for 440 hours before they go out into the field, according to CHP spokesman Mike Martis Jr.

Some worry a dog that alerts on marijuana could taint an otherwise lawful search that turns up illegal guns or other contraband. Local and state police agencies say they’ll work around the legal issues by leaving behind narcotics dogs when out on patrol. Instead, they’ll be brought out once a large-scale grow or trafficking operation is suspected.