Emotional Support Animals (ESA) provide therapeutic comfort for individuals with mental illness or emotional disorders. Often they are small dogs, but not necessarily so. Unlike service animals, ESAs aren’t trained to perform specific tasks like seeing-eye dogs.

While ESAs aren’t allowed in many businesses, owners of these animals are generally authorized to travel in-cabin and without additional fees in the US thanks to the Air Carrier Act with some exceptions; airlines can impose restrictions as to what kind of animals are allowed, require the animals not smell bad, and also be up to date with their vaccinations . While many people have a legitimate need for emotional support, the ESA exception has been known to be abused by pet owners.

The number of purported ESAs on commercial flights has jumped 74% from 2016 to 2017 and the abuse has led to an industry-wide tightening down of rules regarding these support animals, including banning exotic animals such as reptiles and amphibians, farm animals like goats, and requiring documentation from a health professional that the animal is indeed an ESA.