<Li> Dennis Quaid as Ethan Montgomery (adult) <Ul> <Li> KJ Apa as teenage Ethan Montgomery </Li> <Li> Bryce Gheisar as eight - year old Ethan Montgomery </Li> </Ul> </Li> <Ul> <Li> KJ Apa as teenage Ethan Montgomery </Li> <Li> Bryce Gheisar as eight - year old Ethan Montgomery </Li> </Ul> <Li> KJ Apa as teenage Ethan Montgomery </Li> <Li> Bryce Gheisar as eight - year old Ethan Montgomery </Li>

Who plays teenage ethan in a dog's purpose