A new book will highlight a heartwarming friendship between a three-year-old kid and his fluffy best buddy.

Little Buddy and Reagan have garnered fans all over the world, with over 100,000 Instagram followers following up with their charming antics.

Buddy’s friendship evolved when he was adopted by foster parents at the age of 11 months.

Reagan was adopted as an eight-week-old puppy by his foster grandparents, Sandi and Eric Swiridoff, two years ago.

The book’s proceeds will benefit Foster Parents Night Out, a non-profit organisation that works with foster families.

“The touching, true story of Reagan and Little Buddy needed to be told,” Sandi, a nurse, commented.

“I couldn’t keep all of the cuteness to myself.”

“While photos of the two of them appear frequently on his Instagram, the book is different.

“It includes never-before-seen photos highlighting their relationship from the time they first met until now, nearly two years later.”

“Their story is one of a strong bond and a sweet friendship, and includes a few surprises.”

“I am so excited for this book to come out,” Sandi added.

“And I am thrilled that Reagan is able to make a difference in the lives of so many people.”

“Reagan gets along well with children and other dogs; he hasn’t met a dog or person he doesn’t like.”