By Jim Gorant. Gotham Books. $26.

Poster dog, underdog and hero dog all wrapped into one, Wallace is a pit bull that turns heads and dispels myths that all members of his breed are bad.

Gorant, author of “The Lost Dogs: Michael Vick’s Dogs and Their Tale of Rescue and Redemption,” captures the inspiring determination and physicality of a Minnesota shelter dog once scheduled for euthanasia and his dedicated owners’ willingness to coax the very best out of him.

“Wallace” epitomizes the human-animal bond between Roo and himself both in the home – where he helps save a marriage – and the fields of disc competition — where he accomplishes feats with swagger and style.

Roo, a volunteer, and his wife-to-be Clara, an employee, of the Paws & Claws shelter find themselves at odds with the board of directors, after Wallace (named for Rasheed Wallace, Detroit Pistons star) bites another dog at the facility, prompting the board to label him a “dangerous dog,” meaning his days are numbered.

For Roo and Clara, that signifies game on, otherwise known as the War of Wallace.

Wallace’s liberation becomes a mission for the pair as they quickly acknowledge he is not on anyone’s adoption radar.

Roo considers himself a “reasonably good trainer” but he quickly discovers a major challenge – Wallace is not food motivated. Searching for a means of capturing the dog’s interest and enthusiasm, Roo finds a school of training that utilizes play. Hence, weight-pull competition becomes a prime outlet.

As Wallace’s demeanor improves while the pair fosters him, the quest to find him a home prompts no responses, resulting in them adopting Wallace.

A posting on an internal bulletin board at Roo’s work noting, “Anyone interested in starting a disc dog club? Call Josh,” becomes the genesis for a lifetime game changer for everyone. What begins with local competitions in the Rochester, Minn., area springboards into extensive travels to meets nationwide with additional dogs, Josh and friends.

As Wallace exhibits a strong propensity for the sport, others begin to take notice when this once “dangerous dog” and his partner begin piling up placements. Along the way, Roo and Josh opt to enter a new pairs competition with Wallace and recognize instant success.

While the placements are nice, Roo is particularly inspired by a judge’s poignant remark at an awards ceremony that “he would trade it all for one more day in the park with his dog.” In Roo’s mind, this validates Wallace has been worthy of his and Clara’s efforts to save the animal.

“Not bad for a pit bull nobody wanted,” chimes in Clara. . . . “Watching him, he’s just so determined. He sees that thing he wants and he’s not going to let anything stop him from getting it.”

“He never gives me less than 100 percent,” adds Roo. “No matter how bad I throw it, he never quits. He never gives up.”

This isn’t simply a memoir about a guy and a dog. It’s much more: friendships, a marriage on the rocks, battling Wallace’s allergies and shoulder ailment and recognizing at every turn he is a dog bite away from a public-relations disaster.

Eventually, however, Roo and Wallace “outhustled and out hearted all the herding dogs and retrievers and shepherds” to capture the big prize, a Flying Disc Dog Open world championship.

Flowing smoothly throughout, “Wallace” is an uplifting but sobering narrative, accented with an empowering platform for an underdog and his believers to never give up.