The film details how dogs learn to serve people with disabilities and how animals and humans are paired. An Iraqi veteran who became a quadriplegic after a car accident and a 6-year-old with cerebral palsy are among those featured in the film.
The "How I Met Your Mother" star says he was impressed by the strong emotional connection between the service animals and those who rely on them. He owns two dogs.
"Through a Dog's Eyes" debuts April 21 on PBS stations.