Kenzo the 2-year-old German Shepherd knows when it’s time to clock in to his shift as a security K-9 at Hartford Hospital. His demeanor changes from a lap dog snuggling on the couch with his handler’s 6-year-old twins to an energetic, alert watchdog ready to patrol the campus.

Now, Kenzo’s work routine will involve slipping his big paws — which he’s still growing into — through a new, custom-fitted bulletproof vest that he will wear on the job to ensure his safety while working the security detail.

Kenzo is one of six dogs working security in the Hartford HealthCare system. It is the only hospital system in the state to employ K-9s.

Kenzo’s new vest is not only bulletproof but is buoyant, features a back ring to rig things like cameras, has an underbelly impairment protection to protect a K-9’s most vulnerable spot if they charge someone who is armed.

The vest, customized to Kenzo with 27 different specific measurements, was donated by Peter and Suzanne Rappoccio, owners of  Southington-based Sign Pro, which designed the interior and exterior signage at Hartford HealthCare’s building at 100 Pearl St.

Rappoccio said he and his wife had been at a ribbon-cutting ceremony for the building when they met Kenzo. They asked if he had a bulletproof vest, and when they heard he didn’t, they decided to donate the $8,000 vest.

The Rappoccios also surprised Hartford HealthCare by announcing that they’ll be donating a second vest for another dog.

Kenzo’s vest was presented to the pup at a ceremony in Hartford last week. Though he was a bit hesitant to put it on at first, Kenzo seemed comfortable wearing the four-pound vest. His training with the vest would start Thursday night, his handler Kyle Lariviere said.

Kenzo and Lariviere work the night shift at the Hartford Hospital campus, patrolling the buildings and surrounding city streets, responding to any incidents to protect security officers, patients, staff and visitors, and acting as a de-escalation tool when patients or visitors show signs of aggression.

The pair walk the grounds of the hospital throughout the night, always taking a different route to keep Kenzo on his toes — or paws — and Lariviere said they never know what they’re going to run into or what type of situation they’ll encounter when they enter a patient’s room. And they have to be ready for anything.

“We’re there to observe and watch, but we’re there to protect officers if we need to,” said Lariviere, who said their main objective is to keep staff, patients, visitors and other security staff safe.

Kenzo lives with Lariviere and his family, so the two are together round the clock. Lariviere wears a bulletproof vest each shift and said he’s happy that his four-legged partner will now have the same level of security

“It definitely makes me feel better knowing that when I go to work every night he’s going to be safe and protected,” said Lariviere, looking down at Kenzo on Thursday.

Keith Grant, head of operations for Hartford Hospital, said that having K-9s on campus helps make many tense or emotional situations calmer, happier and more healing.

“We are committed to looking at security in many different ways,” said Grant. But when it comes to the K-9 program, Grant said their security role is secondary to the therapeutic element they offer.

“The dogs add a level of therapy and help create a more therapeutic environment,” he said.

The mere presence of a dog, Grant said, can de-escalate and improve a variety of situations that may arise at the hospital.

“Many times the dog just needs to be seen and it changes the conversation in a therapeutic way,” Grant said. “And as an added bonus people love and enjoy dogs.”

Peter Fraser, system director of public safety at Hartford HealthCare, has been working with a fluffy German Shepherd K-9 named Samira, or Sammy, for eight years. Sammy is “the matriarch” of the program, their first K-9, and has been a model for de-escalation tactics, her handler said.

“We saw right away how she could de-escalate behavior quickly,” said Fraser. “Just by stepping between a party and an officer, the focus goes to the K-9.”

Fraser, a former law enforcement officer who has been working with K-9s and raising German shepherds his whole life, said that the hospital dogs are “there to make our staff, our patients and our visitors feel more secure.”

That security, he said, often comes from their mere presence. Though the K-9s are each trained in a specialty, like bomb or weapons detection, they often are just there to help calm things down and interact with the more than 2,000 people who go in and out of the Hartford Hospital lobby each day.

Fraser said that hospital K-9s have to be comfortable interacting with new people all day and night, and that many of their K-9s — like 9-year-old Sammy — have become a staple at the hospital, known by folks who visit often and by residents in the community who see her on her patrol strolls.

“It’s been such a good protection service for us, and we’ve become ambassadors for the hospital,” said Fraser.

Though they are similarly trained, The K-9s at the hospital are a bit different than your average law enforcement K-9s. They are trained to be a bit more approachable, often getting petted by visitors and patients, and to focus on de-escalation and comfort.

“Their temperament is different. They aren’t as outwardly aggressive as police K-9s,” said Fraser, and unlike law enforcement dogs, the dogs can’t be trained to bite.

In Hartford, the Hartford Police Department currently has five patrol K-9s that are German Shepherds and six detection dogs are Labradors.

Each dog is trained in a specific discipline, ranging from evidence recovery to criminal apprehension involving biting techniques, said Hartford Sgt. Joseph Mauro.

Some are also trained for firearms detection, bomb detection or to look for specific drugs, Mauro said. The department just added a K-9 whose role will be more similar to the Hartford HealthCare dogs, a therapy dog for wellness named Kady who has spent the last year comforting folks during criminal trials or bonding with families in Bristol as they mourned two police officers killed on duty, Mauro said.

Hartford police K-9s are trained by the Connecticut State Police’s K-9 unit. The Connecticut State Police have more than 70 K-9s and certify about 200 K-9 teams throughout the state and region. Their dogs are trained for a variety of specialized jobs, like detecting arson accelerants, finding cash and searching for human remains, according to Connecticut State Police Sgt. Anthony Cristy.

State police K-9s are also fitted with bulletproof vests, most of which are donated to the police by residents and businesses throughout the state, said Cristy.