Mack has a nose for trouble. So he's putting that powerful sniffer to good use by helping Maryland's Department of Agriculture sniff out diseases that can devastate bee colonies.

A 2-year-old yellow Labrador retriever, Mack got the job as Maryland's Canine Apiary Inspector last fall, becoming the state's fifth dog to be used for the program. Mack works side by side with his mom, Cybil Preston, to inspect beehives for American foulbrood (AFB) a highly contagious bacterial disease that infects honeybees and can eventually kill an entire colony.

Maryland has had a bee-sniffing dog on staff since 1982. The previous inspector, Klinker, retired last year, leaving Preston in search of a trainable dog to fill Klinker's spot. She wasn't having any luck until friends-of-friends-of-friends told her the sad story of a neighborhood pup who was kept in the garage all day and not given much attention from his owners.

“He needed to get out of that garage, and I needed a trainable dog,” Preston said in a department press release. “It was fate.”

Mack began his training immediately, working with Maryland's Department of Public Safety and Correctional Services K-9 trainers alongside other labs, as well as German shepherds, and Belgian Malinois. But instead of learning to sniff out contraband or drugs, Mack was learning how to find AFB.

So what's a day in the life of a canine apiary inspector like? Mack works during the cooler months from November to April when the bees are less active and he's less likely to get stung. In the field he walks with Preston from hive to hive, sniffing for AFB.

When Mack detects the disease, he sits down to alert Preston that she needs to take a closer look. These inspections help remove infected colonies before the disease has a chance to spread, saving the country's already vulnerable bee population.

Mack can check about 100 hives in 45 minutes. In contrast, Preston performs manual inspections and can only complete about 10 hives in the same amount of time.

"If we want to be efficient, we need a dog," Preston told NPR.

Since Mack is new to the job, his rate of success has not yet been put to the test, but his predecessor, Klinker, was correct in 100 percent of the 13 cases he detected.