Service dog

A trained dog on duty for a person with a disability. A service dog (assistance dog in much of the world) is taught specific tasks: warning of a coming seizure or low blood sugar, picking up dropped things, opening doors, steadying someone who loses balance, or interrupting a panic attack. The handler's disability is often invisible, which is why the vest matters: it tells strangers the dog is working. In many countries a service dog may go where pets can't, into shops, restaurants and public transport.

Three dog emoji, three jobs. 🐕 is any dog or a pet. 🦮, in a stiff harness, is a guide dog for a blind or partially sighted person. 🐕‍🦺 is every other kind of assistance dog, and the safe choice when the task isn't named or the disability isn't visible. It does not mean an emotional support animal, which comforts by being there and has no task training, though people do use it loosely for any comforting dog.

Technically the emoji is a dog 🐕 and a safety vest 🦺 joined by an invisible joiner character, so on an old device you may see the two pictures separately.

Use it to cheer the team, not to pet the dog

In a handler's post it reads as pride or solidarity: a training milestone, a smooth day out, a shop that let the dog in without argument, or a complaint about one that didn't. Trainers and volunteers who raise service puppies use it for their dogs' progress, and disability advocates use it to flag an access topic. Replying follows real-life manners: congratulate the person, don't ask what their disability is, and don't treat the dog as something to pet. Away from disability, it occasionally stands in as a joke for any dog with an important job, or for a friend who is someone's 'support human'.