What species of animal can be an Emotional Support Animal?

The Federal laws that protect Emotional Support Animals and their handlers (the Fair Housing Amendments Act of 1988, Air Carrier Access Act 49 U.S.C. 41705, and Dept. of Transportation 14 C.F.R. Part 382), neither specify nor exclude any animal species or breed. Common sense should prevail, however. For example, although property managers are required to make a reasonable exception to the rules to accommodate a person with an ESA, the justice system would side with the property manager who rejects a tenant who wishes to have a mule as an ESA living inside the apartment. Similarly, airlines may require any animal that is too large to sit between the knees of the disabled passenger and the seat in front of him/her to be crated and transported elsewhere in the plane. Common ESAs include dogs, cats, birds, mice, rats, hedgehogs, rabbits, snakes, miniature pigs, monkeys, and more.