Sources first: this summary is based on the DOJ service animal FAQ and the DOJ 2010 ADA service animal requirements. The official pages are the authority — not this guide.
What counts as a service animal under the ADA
Under the ADA's public-access rules (Titles II and III), a service animal is a dog individually trained to do work or perform tasks directly related to a person's disability. A dog whose only role is comfort — an emotional support animal — is not a service animal under these rules. Psychiatric service dogs individually trained to perform specific tasks do qualify; comfort alone does not.
There is no federal certification or registration
The DOJ confirms there is no federal certification or registration requirement and no "official" registry exists. Owner-training is permitted. However, a dog in training does not yet have ADA public-access rights — protections begin once it is individually trained for its work or tasks. State and local rules can differ, so check yours separately.
What businesses may ask
When it is not obvious that a dog is a service animal, staff may ask only two questions: (1) is the dog required because of a disability, and (2) what work or task has it been trained to perform. They may not ask about a diagnosis, demand a certificate, or request a demonstration.
Control, house-training, and removal
A service dog must be under the handler's control and housebroken. A dog that is out of control and not corrected, or that is not housebroken, may be asked to leave — with the person still offered goods or services without the animal. Even when all rules are followed, there is no absolute public-access guarantee. Miniature horses are covered under separate ADA provisions; see the full official guide.
If you experience access discrimination
Write down what happened — date, location, who was involved, and what was said. You can request the business's policy in writing, review official DOJ information, consult qualified advocates, and file a complaint through the official ADA complaint process.
Scope: this free guide is general education, not legal advice or representation. Housing and air travel are covered by different frameworks than ADA public access and are not addressed here.