Folcroft was able to acquire Sarge from an Ohio breeder who specializes in training police dogs for $10,000 through donors.
He started work last month, joining Umberto, a German shepherd that specializes in drug detection and patrol, and replacing Mackey's former partner, Logan. At age 7, Logan was diagnosed with a progressive spinal condition that left him unable to walk, and he was euthanized in November 2011.
The Center for Animal Referral and Emergency Services (CARES) in Langhorne came to the department's rescue. It donated $3,000 worth of services for Logan before he died, and started a fund-raiser for a replacement.
In all, $21,000 was collected, with Nissan of Devon kicking in about $10,000.
Sarge spends his off hours with Mackey and his family.
"My 4-year-old thinks he is her dog," Mackey said.
On Wednesday, Mackey took his new partner for a quick training run at the Folcroft Fire Department. Sarge bolted from the police cruiser, enjoyed a quick pit stop, and made a beeline toward some frozen goose manure before Mackey called him off.
When it comes time to work, Sarge is all business.
In the firehouse, Mackey had hidden a training aid that mimics explosive material under a couch cushion. On command, Sarge raced through the room, nose to the ground, over chairs and around furniture until he found the decoy.
He sat erect, fixated at the cushion, until Mackey gave the signal and handed him his reward - a blue and orange tennis ball.
Contact Mari A. Schaefer at 610-892-9149, firstname.lastname@example.org or @MariSchaefer on Twitter.