Horses are gentle giants with an amazing ability to help people. 

Articles discussing how and why horses aid people who spend time with them.

The Therapeutic Value of Horses - Psychology Today

PTSD plummets for veterans who try horseback riding - treehugger

Using Equine Therapy as Mental Health Treatment - verywellmind

Evaluation of an equine-assisted therapy program for veterans who identify as ‘wounded, injured or ill’ and their partners - The National Center for Biotechnology Information