BREWER, Maine — Lying on the floor next to his human companion, Colby the dog didn’t seem too interested in the tales Bill Irwin told Thursday evening. In fact, Colby completely ignored all the praise Irwin lavished on him.

“Colby is the best all-around dog that I’ve ever had,” Irwin told nearly 90 people who attended the Bangor Humane Society’s Donor and Friends Reception at the Muddy Rudder restaurant. “He loves to play and have a good time … and yet he’s one of the most diligent workers that I’ve ever had, and I just hope he lives to be 100.”

Colby is Irwin’s fifth guide dog, but despite Colby’s good qualities he isn’t the most famous of Irwin’s dogs.

That would be Orient, with whom Irwin, who is blind, hiked in 1990 the Appalachian Trail from Georgia to Maine. Two books have been written about Irwin’s hike, including a children’s book about Orient.

Irwin is thought to be the only blind person to have completed the Appalachian Trail, which at the time, Irwin said Thursday, measured 2,167.9 miles.

Developing a strong relationship between a human and an animal is key not only to completing that kind of feat, but also in everyday life for a blind person.

“Bonding is the most important thing a human has to do in order to really get to know and have a fellowship with their pets,” the 69-year-old Irwin said before he gave his speech. “Of course, he’s not a pet, and it’s even more critical because that bonding makes a difference between life and death for a blind person.”

A North Carolina native who now lives in Sebec, Irwin is a motivational speaker and has addressed dozens of international companies, educational institutions and organizations on topics such as leadership management, recovering from addiction and diversity. Irwin has dealt with alcoholism.

Without Orient, who retired about five years after completing the Appalachian Trail and died a few years later, Irwin might not have found the way to Maine, he said. Orient was truly guiding his human master.

“By the time we got to Massachusetts, Orient could read the blazes on the rocks and trees,” Irwin said. “He followed the blazes from Massachusetts on into New Hampshire.”

Several members of the audience teared up as Irwin also shared stories of his other dogs, to which he developed strong attachments. When one of his former guide dogs, Jorie, developed hip trouble, Irwin said he would carry the dog up and down stairs.

“People would stop me and say, ‘What is this? This dog’s supposed to be helping you,’” Irwin said. “I said, this dog helped me every step of the way for 10 years, and I’m going to help him for the rest of his life.”

In fact, Irwin said he can’t bear to send his retired dogs to a retirement center operated by

Seeing Eye Inc., a Morristown, N.J.-based organization that trains guide dogs.

“The attachment was too great,” he said. Irwin instead gets a new guide dog and keeps the old one as well.

“So all my dogs get to retire early and get fat and lazy, eat table scraps and do whatever they want to do for the rest of their lives.”