The young pit bull caught on camera attacking a Pasadena Independent School District sixth grader is scheduled to be euthanized on Sunday or Monday.
The 42-pound dog will then be tested for rabies.
The student involved in the attack will not be immediately tested for rabies, her mother said.
On Wednesday, the dog climbed aboard a school bus filled with students. Pasadena ISD has said it is investigating the incident.
On Friday, KPRC Local 2 learned some of the district's findings, including how the dog managed to get on the school bus.
"The bus driver said it went under the divider and then went under the seats and came out near the back of the bus," Renea Ivy-Sims, an assistant superintendent, said by phone.
The dog was seen biting student Selena Diaz on the lower leg several times.
"She was injured. She was bleeding. I mean, you can see the dog bites," mother Angie Diaz said.
Selena Diaz is now back at school.
On the video, it is clear that the driver of the bus pulled the dog off the girl, but Angie Diaz said she is disappointed that nobody came to her daughter's aid sooner and she wants to know why the school bus driver continued his route.
KPRC Local 2 posed the same question to school district officials.
"There was no blood outside the child's pants, so the bus driver picked up the next two or three kids. This happened at 7:55. He was at school by 8:15. We are still investigating and we don't want to minimize what happened," Ivy-Sims said.
Ivy-Sims said the bus driver was not on his afternoon route Friday and was facing disciplinary measures, but would not elaborate.