An emotional support animal (ESA) is a companion animal that provides therapeutic benefit, such as alleviating or mitigating some symptoms of the disability, to an individual with a mental or psychiatric disability. Emotional support animals are typically dogs and cats but may include other animals. A person must meet the federal definition of disability and must have a note from a physician or other medical professional stating that the person has that disability and that the emotional support animal provides a benefit for the individual with the disability.

Disabilities may include conditions such as blindness, hearing impairment, mobility impairment, HIV infection, mental retardation, alcoholism, drug addiction, chronic fatigue, learning disability, head injury, and mental illness.

To learn more visit the links below:

https://en.wikipedia.org/wiki/Emotional_support_animal
http://www.justice.gov/crt/fair-housing-act-1#disability
http://www.hud.gov/offices/fheo/FINALRULE/Pet_Ownership_Final_Rule.pdf

Photo:
By National Institute for Occupational Safety and Health (NIOSH) from USA (Assistance Dog in Training) [Public domain], via Wikimedia Commons