I have worked for 2 major service dog schools over a period of 11 years.
* only dogs and mini horses (as guides) are covered under ADA law - they are given FULL access rights.
* ESAs are allowed on planes and housing that may not normally allow pets - but that is the ONLY access they are given.
* it is illegal to require any certification proof of a service animal. (This is a hot topic among service dog handlers and constantly debated...it has a lot to do with privacy issues.) However, the FAA is allowed to ask for different types of documentation, including a health certificate, for any animal flying.
* fake service animals can cause a lot of harm to real service animals - because they are not trained, they might attack other animals, they make people 2nd guess real service animals and cause more grief for handlers, etc.
* service animals are allowed where the public may go, as long as it does not interfere with how the business is run and accommodations have to be made if a dog isn't allowed - example, dog is allowed in doctor's office but not the operating room (since only qualified personnel are allowed there); Disney allows dogs on most rides except where it could inhibit the running of the ride (dogs aren't allowed on coasters but Disney has a crate nearby to put dogs in if handler wants to ride without dog).
* businesses can ask 2 questions: is that a service animal? What tasks is the dog trained to do for you? Tasks have to be physical, not just "comfort." If a dog is very dirty or is causing a scene by barking or snapping or lunging at people, the law protects a business to tell the handler to remove the animal.
* it is punshiable with JAIL TIME in the state of Florida to pass off a fake service dog as a real one. This would require the business to call the police, etc.
* fake service dogs are pretty easy to recognize - dog is on a flexi leash or is loose, dog is in a stroller (OCCASIONALLY the dog may still be a service dog in this case, but usually not as most service dogs need to have access to their handler to perform their tasks), the dog is badly behaved, the dog is sitting on a table or on a chair (again, occasionally could still be a service dog but most handlers would prefer their dog to be as "invisible" as possible).
* quick definitions: SERVICE dog performs tasks for a specific person with a disability (Assistance Dogs International requires their members to train a minimum of 3 tasks that are for the disability), they have FULL access rights; EMOTIONAL support animals do not have to be trained and are for people who have a need for a "comfort" animal, usually something like anxiety, they have access rights on planes and housing only; THERAPY dogs are trained to provide "comfort" etc for a group of people such as a hospital or school and have NO access rights but are cleared through the business for which they volunteer.