When her family's 2-year-old, 8-pound papillon taps Caroline Kahle with his paw, it's not just a sign of affection.

It's an act of protection.

Muggsy is a service dog who spends nearly every hour of every day with Caroline, who has Type 1 diabetes.

The tap is Muggsy's warning that Caroline's blood sugar has fallen or risen to a dangerous level.

"A lot of times I wouldn't even be aware I was having a problem with my blood-sugar level unless he was there to warn me," Caroline said.

By the time a person with Type 1 diabetes is showing symptoms of a problem, the situation may already be dire, said Caroline's mother, Bridget Kahle.

"Having Muggsy in our family has given us tremendous peace of mind," she said. "We don't have to worry as much."

Caroline, 14, is an eighth-grader at Edison Intermediate/Larson Middle School. She was diagnosed in 2011.

"Muggsy comes to school with me each day," she said. "He's always around me, although when I play softball in the spring, I'll hand him over to Ellie."

"The teacher and the other students love it," said Ellie, Caroline's twin sister. "He's not there to play, but it's just nice to have a dog in the school. It helps brighten the atmosphere."

The Kahles signed up two years ago to receive a dog from 4 Paws for Ability, a Xenia-based organization that places service dogs with children coping with various types of disabilities and medical conditions.

Each dog goes through more than a year of training, Bridget said.

The training includes a semester-long stay with a college student.

"It's to get them used to living with someone and being in a classroom and around a lot of people," Caroline said. "Muggsy's a 'graduate' of the University of Kentucky."

The Kahles also spent two weeks training with Muggsy at the 4 Paws facility in Xenia.

He came home to live with the family in July 2016.

"He gets along great with our other dogs, who are golden retrievers," Ellie said. "They love to play with him, I think, because he's so small."

One of the retrievers, Darby, is 9 years old. The Kahles obtained their 1-year-old retriever, George, from 4 Paws.

"George was undergoing training to be matched with a child on the autism spectrum, but he failed," Bridget said.

"He just didn't like walking on slippery floors," Ellie said, "but he's such a gentle, good dog."

George is so gentle that Ellie plans to undergo training to take George to hospitals and nursing homes as a comfort dog.

"It's something I really wanted to do," she said. "It all came from seeing what Muggsy has been able to do for my sister."

"I've got a really close bond with him," Caroline said. "He's a lot more than a pet for our family."

Bridget said she and her husband, John, don't have to worry as much about a problem arising while Caroline is sleeping or when she goes off to college.

"He's been amazing," she said. "There have been a number of times he alerted Caroline to a situation and she was able to address it before it got serious."

In one recent incident, the continuous glucose monitor Caroline wears went on the fritz.

"It's a great device because it's connected to an app on her phone and an app on my phone, but this day, for some reason, it just stopped working," Bridget said. "Well, the device may not have been working, but Muggsy was on the ball. He noticed a problem with Caroline's blood sugar and let her know. The dog worked when the technology didn't."

To help cover the family's $15,000 share of the cost of training Muggsy, Caroline and Ellie organized a number of fundraising projects, including selling T-shirts and homemade dog treats.

The family also received support from the Grandview community, Bridget said.

"We were so overwhelmed by the generosity of family, friends and the community," she said. "Caroline is on the track team and her teammates held a bake sale and raised $300. We're really grateful to everyone who gave us their support."