GROTON -- By night, K-9 cop Lola fights crime.
By day, she fights cancer.
The eight-year-old black Lab, the town's first and only four-legged officer, was diagnosed with high grade B-cell lymphoma in early August. Veterinarians performed a nephrectomy on her on Sept. 11.
But neither the cancer, nor a missing kidney, could deter Lola from her duties.
"She likes to work," said Groton Police Officer Nick Beltz, her handler. "She's at the door waiting for me, ready to go every night."
Beltz and Lola work the overnight shift. Lola specializes in drug sniffing and tracking.
Beltz explained that he first approached management in 2012 about the need for a K-9 and, after very little wrangling, Lola reported for duty. The pair attended training camp and have been loyal partners since.
"She's a part of our family," said Beltz, whose two young children also approve of Lola's performance.
"I was floored when I first heard the diagnosis," he said. "I took her to the vet because she had a bladder infection."
The doctors discovered that her left kidney was double its normal size, thanks to a tumor that had rooted itself there.
The tumor was surgically removed and Lola was back on her feet in a few days. She is currently undergoing a 19-week chemotherapy treatment that Beltz says makes "the outlook very good. Her behavior is getting back to normal and the cancer is in remission."
Beltz said Lola has at least two dozen drug finds in her six years on the force.
He also said Lola tracked down a high school cross-country runner who had become lost in the woods. When the police, guided by Lola, found the teenager, she was shivering against a cold January afternoon.
Lola's other job is public relations, visiting schools and attending community events. Last week she visited the north building at Groton-Dunstable Regional Middle School.
The dozen or so children and staff asked Beltz about the bald square on Lola's back.
"That's where the doctors had to shave her to give her medicine," he explained.
One student, Cameron DeLoureiro, said, "I like her, she works as a police officer because she has a good nose for sniffing."
Students were fascinated by the authentic badge that hangs around the dog's neck from a collar with the words "K9 police" stitched into it.
For Beltz, Lola is more than an unflinching police officer and trusted partner.
"We are together almost constantly. We live together and we work together," he said, understanding that at some point, Lola will hang up her badge.