When I tell people that Joey is a certified therapy dog, they often say something like, “Oh, you must love taking him with you everywhere.”

That statement is at the crux of the therapy dog versus service dog versus support dog misperception. A therapy dog is not a service dog, and a service dog is not a support dog. Most of the time. But sometimes it is.

Confused? Hopefully, I can clear some of those cobwebs of confusion.

Therapy dogs

Therapy dogs like Joey provide comfort to people in hospitals, nursing homes, schools, prisons, courts and other institutions, or act as a connection to patients in therapeutic settings.

Generally, the dog must pass behavior, temperament, and handling tests and successfully complete several supervised field visits before being granted certification.

But … therapy dogs are NOT service dogs.

Under law, therapy dogs don’t fall under the protection of the Americans with Disabilities Act (ADA), which means they cannot enter businesses or public places that disallow animals (such as restaurants or grocery stores), or accompany their human companion on public transportation unless expressly permitted.

Service dogs

By comparison, a service dog is covered by the ADA, which requires that these animals be “individually trained to do work or perform tasks for a person with a disability.” These activities might be assisting a blind person or sounding an alert when their human has a seizure. Psychiatric service dogs, trained to assist people with serious disorders such as post-traumatic stress, also fall under this classification.

Because they’re protected under the ADA, service dogs may go anywhere with their human companion that the public is permitted, including restaurants, hotels, and on any public transportation.

Almost without exception, service dogs will be wearing some sort of special jacket, vest, or harness that often includes a statement such as, “Please don’t pet me: I’m working.”

You must always respect this caution unless the person gives you explicit permission to interact with the animal.

Emotional support animals

The category that’s stirred up the most controversy is the emotional support animal, or ESA. Broadly speaking, an ESA is a companion animal that provides comfort or relief to their human, but is not trained to perform specific tasks related to that person’s mental or emotional condition. These animals do not qualify as psychiatric service dogs, and are not protected under the ADA.

To qualify as an emotional support animal, the dog’s owner must obtain a letter from a licensed mental health professional certifying that the person has a specific emotional disability, not just the need for companionship.

And that’s where the problems surface, thanks in large part to the Air Carrier Access Act, which allows individuals to bring an emotional support animal on board a plane at no additional cost. Over the last few years, literally hundreds of websites have popped up promising to deliver a diagnosis — sight-unseen — and provide an ESA documentation letter for less than $100.

That’s given rise to increasing problems with pets on airplanes: Fifi piddling in the aisle, Fido biting a flight attendant, Buster barking nonstop from Sacramento to Chicago. Many of these supposed-support animals are in fact nothing but family pets — some of them untrained or unsocialized — wearing fake assistance animal paraphernalia and sporting phony service and support dog certifications. This sort of deceptive scheme makes it all the harder for those who genuinely need an emotional support or service animal.

So whether you’re meeting up with a service dog, therapy dog, or emotional support animal, hopefully now you’ll have a better idea of what they are, what they do, and how you can interact with them.

Joan Merriam lives in northern California with her Golden Retriever Joey, her Maine Coon cat Indy, and the abiding spirit of her beloved Golden Retriever Casey in whose memory this column is named. You can reach Joan at joan@joanmerriam.com.