Remember: just because it looks cute and friendly, doesn’t mean you should touch, call or in any way distract a service dog without permission. Here’s what can happen if you do.

After someone stopped to pet a teenage girl’s service dog, that person learned the hard way why these important animals should never be distracted. Indeed, it took just a matter of moments for this dog’s owner to find herself in serious trouble.

Of course, it is sometimes hard to resist the adorableness of a cute, friendly dog. And, in fact, service dogs may be especially tempting to pet because of their naturally peaceful demeanor. However, the story of a Texan teen named Hailey Ashmore illustrates exactly why we should leave service dogs alone no matter what.

At the time of this incident, Ashmore was just 16 years old. The teenager has several serious medical conditions, including epilepsy, Ehlers-Danlos syndrome, postural orthostatic tachycardia syndrome, reactive hypoglycemia and gastroparesis. She also deals with asthma and severe allergies.

Despite this, Ashmore was once an active high school student, being both a dancer on the varsity drill team and a member of the student council. But her deteriorating health meant that she had to cut back on her activities. In fact, even her social life was limited because her medical flare-ups forced her to take classes online.

In 2014, though, the teen was given service dog Flynn. He was just a an 11-week-old pup at that time, but he meant that Ashmore was, and still is, able to get around outside.

Not everyone is so fortunate. “To get a service dog you must be disabled to the point where you can no longer function at a normal quality of life without the assistance of service dogs,” Ashmore has explained.

Ashmore had to furthermore spend thousands of dollars and two dedicated years training Flynn to be her service dog. The two of them went through the process with Stimming Paws Assistance Dogs, an organization that specializes in this field.

Today, Flynn and Ashmore go just about everywhere together. Indeed, the Australian Shepherd plays a number of important roles in Ashmore’s everyday life.

For example, some of Flynn’s duties include opening doors for Ashmore and fetching her parents when needed. But one of Flynn’s most important jobs is to be a medical alert dog. This means that he can sense when Ashmore is about to have a seizure and is trained to alert her before it occurs.

In fact, in 2015 it was this job from which Flynn was distracted, and it came at a time when Ashmore needed him most. Ashmore was at her dad’s workplace when a man decided to give Flynn a few moments of attention.

The day of the incident, Flynn was only around seven months old and still in service dog training school. He knew his job, however, and he was on duty.

Flynn was even wearing the requisite service dog vest that showed he was working. To reinforce the point, the back of Flynn’s vest has “STOP” in large letters on it to deter people from petting him.

None of this, however, made any difference. As soon as Ashmore realized the situation, “I immediately told him to stop [petting Flynn],” she told The Dodo. But the damage had already been done.

“Seizure alert service dogs generally have a timeframe between when they alert to when the seizure actually happens,” said Ashmore. Flynn, for instance, usually gave Ashmore a ten-minute warning of a seizure.

That time window allows Ashmore to get her drugs or get help and move to a safe spot so that she won’t get hurt during the seizure. But because Flynn was no longer focused on Ashmore, he missed the first subtle signals that would have cued him to bark and alert her to the danger.

Once Ashmore spoke up and Flynn redirected his focus, however, he immediately gave her the warning. Unfortunately, it was too late. “I am used to him giving me ten minute warnings, so when he alerted that’s what I thought I had,” Ashmore told The Dodo.

This time, though, Ashmore had a seizure almost immediately. “Out of nowhere I remember the world going black. I woke up with Flynn on top of my legs and my father cradling my head,” Ashmore recounted.

Indeed, Ashmore fell onto the floor after she began to seize, and she received rug burns on her face from the carpet. “On the whole left side of my face there was a terrible sting that made me tear up,” she said.

While the rug burns on Ashmore’s face eventually healed, her story still serves as an important reminder to all dog lovers out there. Ashmore later posted an Instagram photo of her face rubbed raw and wrote, “My service dog is my lifeline. I don’t say that to be cute. He helps keep me alive just like life support. If he gets distracted this happens.”

Ashmore added, “Please do not pet, call, or do anything to distract service dogs without explicit permission from the handler. Next time, instead of a rug burn, somebody could get seriously hurt or die.” So if you see a service dog working in public, just remember that even a friendly ear-scratch could jeopardize the life of the human that dog is protecting.