El libro en el que se basa la película Tu mejor amigo (A dog's purpose).

Reconfortante, profunda y repleta de momentos de felicidad y risas, La razón de estar contigo no es tan solo la historia emotiva de las múltiples vidas de un perro, es también la narración de las relaciones de los humanos vistas desde los ojos de un perro y de los inquebrantables lazos que existen entre el hombre y su mejor amigo.
Esta conmovedora historia nos enseñará que el amor nunca muere, que nuestros verdaderos amigos estarán siempre a nuestro lado y que cada criatura en la Tierra ha nacido con algún propósito. «Adoro esta novela, no pude parar de leer. Me hizo pensar acerca de los propósitos de la vida. Al final, lloré y reí.
The New York Times

«Una mezcla perfecta entre Marley y yo y Martes con mi viejo profesor.
Kirkus Reviews ENGLISH DESCRIPTION A Dog's Purpose―the #1 New York Times bestseller and major motion picture―is a perfect gift to introduce dog lovers to this wonderful series. Based on the beloved bestselling novel by W. Bruce Cameron, A Dog's Purpose, from director Lasse Hallström (The Cider House Rules, Dear John, The 100-Foot Journey), shares the soulful and surprising story of one devoted dog (voiced by Josh Gad) who finds the meaning of his own existence through the lives of the humans he teaches to laugh and love. The family film told from the dog's perspective also stars Britt Robertson, KJ Apa, John Ortiz, Peggy Lipton, Juliet Rylance, Luke Kirby, Pooch Hall and Dennis Quaid. A Dog's Purpose is produced by Gavin Polone (Zombieland, TV's Gilmore Girls). The film from Amblin Entertainment and Walden Media will be distributed by Universal Pictures. Screenplay by W. Bruce Cameron & Cathryn Michon and Audrey Wells and Maya Forbes & Wally Wolodarsky. Heartwarming, insightful, and often laugh-out-loud funny, A Dog's Purpose is not only the emotional and hilarious story of a dog's many lives, but also a dog's-eye commentary on human relationships and the unbreakable bonds between man and man's best friend. This moving and beautifully crafted story teaches us that love never dies, that our true friends are always with us, and that every creature on earth is born with a purpose. Bailey's story continues in A Dog's Journey, the charming New York Times and USA Today bestselling direct sequel to A Dog's Purpose. A Dog's Purpose Series
#1 A Dog's Purpose
#2 A Dog's Journey
#3 A Dog's Promise Books for Young Readers
Ellie's Story: A Dog'