People are generally aware that (no matter how cute they are) you should not approach a service dog while they’re on the job. That said, a Twitter post gone viral has made it clear many do not know how to react if a service dog approaches them without their owner.
Twitter user Melissa Hope shared Tessa Connaughton’s personal story about how she tripped and fell flat on her face. Because Tessa was prone to seizures, her service dog was trained to get an adult if Tessa was down 
in need of assistance. The recounted incident was ultimately harmless: Tessa had only tripped, not had a seizure. But when she had composed herself she found her dog had been trying to get the attention of a very annoyed woman, swatting at him and telling him to go away.
“If a service dog without a person approaches you, it means the person is down and in need of help,” Tessa wrote in the original post. “Don’t get scared, don’t get annoyed, follow the dog! If it had been an emergency situation, I could have vomited and choked, I could have hit my head, I could have had so many things happen to me…If what’s-his-face could understand that Lassie wanted him to go to the well, you can figure out that a dog in a vest proclaiming it a service dog wants you to follow him.”
The viral post prompted a story on the Today Show where their dog trainer, Olivia Poff, explained some of the ways a service dog may try to get your attention, like nudging a person’s leg with their nose. “But in general, the bottom line is if you see the dog in a vest without a person attached to it: follow them.” Olivia went on to explain that there’s no secret verbal cue to let the dog know you’re willing to help; all you need to do is follow them.
Tessa’s post also explained that they were going to further train her service dog so that if the first person was uncooperative he would know to move on. Olivia Poff underscored this point in the Today segment: “Persistency is something that you can definitely increase in terms of behavior, but that’s something you would have to train and work on.”
For Melissa Hope’s part, the actress/singer/dancer/writer was not particularly looking for this sort of Tweet to be her viral breakout. Apparently after getting flack from other Twitter users with differing opinions or with service dogs trained to react differently (because what is Twitter but a place to attack other people?), Melissa deleted the original post: “That’s it. [I’ve] had it. The message is coming down. Very glad for whatever good it did or whomever [it] helped. But done with this!”
Sadly, Tessa Connaughton passed away from complications of epilepsy about 7 months after her Tumblr PSA went viral.