Executive producer Don Hardy first teamed up with Guide Dogs for the Blind for a 2018 documentary that followed a litter of puppies from their birth through two years of training to become guide dogs. Entitled “Pick of the Litter,” the documentary showcased what it takes for these dogs (and the humans who raise them) to make the cut to graduate the intensive program and get paired with a visually impaired person. But now, just a year later, the journey continues with a Disney Plus docuseries of the same name.

“As the film was getting ready to be released somebody from Disney saw a trailer for it and that started the conversation with Disney Plus to do it as a series,” Hardy said at a panel discussion for the new series, which Variety moderated. “From the beginning, we said we didn’t want to disrupt any of the training. That was the biggest thing because the most important part is training more dogs, and so we don’t want to be intrusive.”

In order to not get in the way of training but still capture all of the action — and emotion — the production team on the film came up with a camera technique that proved pivotal for the docuseries as well. Using a “smaller camera on a gimbal that then goes into a monopod that we can flip upside down,” Hardy said, they were able to not only get the camera down low enough to be at the dogs’ eye levels but also “allow us to keep up — because they’re really fast.”

Guide Dogs for the Blind CEO Chris Benninger noted that having the camera crew around the specific litter of puppies being filmed actually aided in their training: “It’s terrific for training in focus because that’s part of being a guide dog is learning how to focus — ignoring the cat and the dog, as well as the camera.”

But Benninger admitted that when Hardy and his producing partner on the film, Dana Nachman, first brought up this in-depth look at the process of training a dog to be a guide dog, there was some “negotiation” that had to come together to make sure the puppy raisers would be comfortable opening their homes up to cameras. Hardy and Nachman had a relationship with the organization from years back, after they covered the non-profit during their days at NBC News in the Bay Area. (Guide Dogs for the Blind is housed in San Rafael, Calif.)

“We ended up leaving news and started to make documentary films and years later we were standing at a film festival and rehashing ideas that had been lost along the way. This one came back up, and one of us said, ‘What if we just followed one litter of puppies?’ So that’s what we approached Chris and her team with,” recalled Hardy.

Benninger was eager to further spread the organization’s mission, which is “to help those who are blind or visually impaired to gain independence through the use of a guide dog.” To date, Guide Dogs for the Blind boasts the largest population for a guide dog school in North America, with more than 2,200 active guide dog teams currently in the field and more than 15,000 graduated teams since it was founded in 1942. But it’s not an easy road to get a dog trained, graduated and matched with a visually impaired person.

“It’s a huge communal vision. We estimate that in order to get a dog to guide there’s, at one point or another, at least 50 people who are involved. It takes a huge commitment to do what we do,” Benninger said.

The feature-length documentary focused on following a litter of puppies from birth through their early puppy raising, but the docuseries goes deeper into what happens when dogs move from a puppy raiser’s house back to the Guide Dogs for the Blind campus for the next step in their training.

“We had to learn from the [puppy] raisers in the series about what those puppies had been like, growing up. We get backstory through their stories,” said executive producer Mary Celenza. “You get to see the dogs back on campus, training with two incredible instructors.”

The docuseries starts in the puppy raisers’ homes, meeting six specific dogs and the families who cared for them for the past year-plus of their lives. Hardy said there was a casting process for this project, which was a first for him, coming from the documentary world. Casting wasn’t about trying to force a narrative or find dogs with great diversity in personality or skills (rather, they just learned how to look for camera-friendly traits from the dogs during the feature process and did their best to capture them here). However, the people around the dogs had to be comfortable and willing to go through the added steps of working with production, in addition to what Benninger pointed out is a “24/7 investment” of raising the puppy.

“Our puppy raisers are absolutely integral to our process because they train all of our puppies in house skills and in introducing them to the world, all of [which] we cannot do on our campus,” she said.

The docuseries then follows as those raisers have their final evaluation and say goodbye to the dogs. Then, approximately 12 weeks of working with instructors comes into play, but there is also time to explore the different dogs’ personalities, as well as moments where the dogs have “the opportunity to be dogs and play,” previewed Hardy. While a misconception about service dogs is often that they are always working, the docuseries pays careful attention to showcase the dogs both in and out of their harnesses. One particular moment that Hardy thought would be fun for viewers is a slow-motion sequence of a dog being trained wearing booties.

Spending time getting to know the people who are waiting for the dogs on the other end of graduation was also important to the storytelling of the docuseries.

“The matching process is a huge process,” Benninger said, adding that they often spend nine months preparing a person to get a guide dog and determining which guide dog would be the best fit. “Our client comes to class; we do a home interview. It’s really important for us to fully understand what someone’s lifestyle is and what they’re going to be asking of their guide dog.”

In addition to how often a guide dog will be traveling versus just going around a person’s neighborhood, Benninger shared they also match based on personality and preference: “Some people like Goldens, some people like Labs, some people like females, some people like males. If you have some color perception you may be able to see dark colors, you may only be able to see light colors. We’re going to match you. If you’re outgoing, we’ll match you with a dog that has an outgoing personality.”

And, she admitted, they can’t count out a little bit of “magic” when it comes to making that perfect match.

“We had a client that was a huge ‘Happy Days’ fan. Every year he and his family traveled from Portland to Milwaukee to go to the Fonzie statue. Guess what the name of his dog was? Fonzie. That’s part of the magic!” she said.

With such high stakes on the line and such emotion in seeing these dogs learn important new skills but also have to be sent off to new people, Hardy admitted there are a lot of ups and downs and a roller coast of emotion delivered in the docuseries.

“We just wanted to see what was going to happen with the six dogs that we were following,” Celenza said. “Whether a dog is career changed and becomes a fantastic pet, or a dog is career changed to other organizations for service…or they can be matched with a person who is visually impaired and be a best friend, companion and partner, I feel like any of those endings is happy.”

“Pick of the Litter” launches Dec. 20 on Disney Plus.