The work of Canine Assistants founder Jennifer Arnold, who trains dogs to help people with disabilities, is examined. The doc also details the canine-recipient matching process and shows the difference the dogs make in the recipients' lives. Among the cases: Iraq War veteran Bryson Casey, who was involved in a car accident after returning home that left him a quadriplegic; a 6-year-old boy with cerebral palsy; an 11-year-old girl with a rare form of epilepsy. Neil Patrick Harris narrates.