MANTECA, Calif. -- A dog that assists an autistic preschool student was denied entrance Monday at the boy's school, the child's mother said.

Jayden Qualls, 4 ½, tried to attend his first day of school Monday at McFall Preschool in Manteca, about 70 miles east of San Francisco. Qualls' family said he needs Houdini, a 2-year-old male Labrador retriever shepherd mix, to help him walk, reported KCRA-TV in Sacramento.

Tara Qualls, the boy's mother, said the school's principal made the decision not to allow the dog into the school.

School district officials said they need to determine if Houdini is a service dog or a companion dog. They also need more time to find out if the dog is warranted at the school and if so, how he fits into the flow.

The Americans with Disabilities Act gives Jayden the right to have Houdini in school, Qualls said.

Jayden's parents bought Houdini for $13,000 from a nonprofit called Autism Services Dogs of America. The dog helps their son with walking, staying alert and emotional outbursts, they said.

There are 125 students at McFall Preschool with developmental disabilities, including autism, the San Joaquin County Office of Education said.