But for some reason Tiffany Denise Allen, who was off duty at the time, got annoyed with the service dog she brought with her and started to follow her around the store.
Then she punched her in the face in the parking lot.
Surveillance video shows McDonald's employees trying to restrain their co-worker, cops wrote in the warrant.
J.M. and Jan Owens, who operate the store on Bells Ferry Road, said they're cooperating with police.
They said: "At our McDonald's restaurant, we respect and value our customers. Their safety and well-being is always a top priority."
"We strive to comply with all applicable laws, including the Americans with Disabilities Act. It is our policy to make our restaurants accessible to all customers, including those with disabilities and special needs, whether or not they need the assistance of service animals."
McDonald's officials say that she is no longer employed by the store.