Autism is a complicated condition, and is not the same from individual to individual. Gus' seizure disorder makes his medical care even more complicated. Schools have different policies as to how to handle service animals, and I thought that the way the school dealt with Chester was true to life. Since Gus lacked skills in dealing with other students, I can see how a classroom teacher might encourage children to interact with Chester as long as they also included Gus, even though children are usually encouraged to leave service animals alone.
Dog stories like A Dog's Purpose are becoming very popular, and Chester's tale will be popular with readers who enjoy Klimo's Dog Diaries, Pyron's A Dog's Way Home, and Martin's Everything for a Dog.