The 2010 Amendments to the ADA limited the definition of a service animal. This has caused confusion for housing providers and employers. Keep in mind that Section 504 of the Rehabilitation Act and the Fair Housing Act apply to housing as well and HUD has construed the definition of a service animal more broadly than the ADA, as amended. Here is HUD guidance on how the ADA requirements for public accommodations (stores, restaurants, etc.) differ from housing requirements: https://portal.hud.gov/hudportal/documents/huddoc?id=servanimals_ntcfheo2013-01.pdf.
In summary, the ADA has limited the definition of a service animal under Titles II and III of the ADA to only dogs, and has specifically excluded such animals that only provide "emotional support." In short, these limitations on the definition of a service animal do NOT apply to housing. If you require the service of an emotional support animal to use and enjoy your dwelling, your rights may be protected under the HUD interpretation of laws applicable to equal housing opportunities to people with disabilities, despite the limitations contained in the ADA, as amended. DOJ guidance further explains how the revised ADA definition of service animals applies only under the ADA and NOT under the Fair Housing Act or Air Carrier Access Act (applicable to travel aboard commercial airlines). http://www.ada.gov/service_animals_2010.htm. The result is, an emotional support animal is likely protected at home or on airline travel, but not necessarily while dining out or shopping.
Moreover, employers subject to Title I of the ADA may not necessarily refuse accommodation to employees with disabilities based on the revised definition of a service animal under Titles II and III of the ADA. It is certainly conceivable that a comfort animal could be a reasonable accommodation necessary to an employee's performance of the essential functions of his or her job that would not unduly burden the employer. These determinations must be made on a case by case basis and blanket exclusion of comfort animals without further consideration is likely violative of an employer's obligations under Title I of the ADA.