The recent refusal of an airline to allow a peacock as an emotional support animal has highlighted the use of animals to aid humans.
The use of support animals, especially guide dogs and now seizure dogs, is almost universally accepted, and they are welcomed by both public acceptance and the law. The few cafe owners that tried to ban guide dogs on the grounds of hygiene found that this was both illegal and improper.5 comments on this story
The use of emotional support animals seems to be a more recent occurrence and is not so clear-cut. To be considered, the person has to have a disability that is certified by a medical authority. There seems to be no precise list of what animals are acceptable, although snakes on a plane are more likely to only be in the films on the plane. There are people who won't or can't fly on planes for any number of reasons, and this may be a time where the comfort of the many outweigh that of the individual.
In the old days, emotional support was provided by Valium and sleeping tablets, which might still be the best option, seeing as toilet training a gorilla is quite difficult.