Why precise terms matter
In everyday conversation, "service dog," "support dog" and "therapy dog" can sound interchangeable. In the law, they are not. Each federal law that touches on animals uses its own vocabulary, and a single word can decide whether a business, landlord or airline has to make room for your dog.
For example, the Americans with Disabilities Act (ADA) defines a service animal as a dog individually trained to do work or perform tasks for a person with a disability. The Department of Justice is clear that a dog whose only role is comfort or emotional support does not meet that definition. That one distinction, trained task versus comfort, runs through almost every question people ask about psychiatric service dogs.
Housing and air travel add their own terms. The Fair Housing Act uses the broader idea of an assistance animal, while airlines follow the Air Carrier Access Act and Department of Transportation forms. Knowing which word belongs to which law helps you understand what you can be asked for, and what you can't.
How to use this glossary
Each entry starts with a one-line definition, then explains where the term comes from, how it applies to people with psychiatric disabilities, and common misunderstandings. Every entry lists the government or professional sources it relies on so you can read the original language yourself.
If you're new to the topic, start with psychiatric service dog, service animal and work or tasks. Those three entries explain the core idea that a trained task, not a diagnosis or a vest, is what makes a dog a service animal under federal law.
Glossary terms by topic
The entries fall into a few natural groups. You can read them in any order, and each one links to related terms.
- Animal types: psychiatric service dog, service animal, emotional support animal, assistance animal, miniature horse and service dog in training.
- Training: task training, work or tasks, owner training, public access test and the AKC Canine Good Citizen program.
- Legal concepts: disability under the ADA, reasonable accommodation, direct threat, undue burden and misrepresentation.
- Housing: the Fair Housing Act, HUD's assistance animal guidance (including the 2025 withdrawal of its 2020 notice), no-pet policies and pet deposits.
- Air travel: the Air Carrier Access Act and the DOT Service Animal Air Transportation Form.
- People and paperwork: handler, licensed mental health professional, LCSW, psychiatrist, vests and so-called registries.
Glossary limitations
These definitions are educational summaries, not legal advice. Laws change, agencies update guidance and states can add their own rules, so check the linked sources or speak with an attorney if you face a specific dispute.
It's also worth knowing up front that there is no federal registry, certificate or ID card for service dogs. Under the ADA, a psychiatric service dog letter is not needed for public access and does not grant it. A letter from a licensed clinician is mainly useful when a housing provider asks for reliable documentation of a disability-related need for the animal, or as background when you plan travel.
If you are in crisis or thinking about harming yourself, call or text 988 to reach the 988 Suicide & Crisis Lifeline, or call 911 in an emergency.