This study is being carried out to learn more about the effects of Therapeutic Horseback Riding (THR) for children and adolescents with an autism spectrum disorder (ASD). This treatment is very popular and horseback riding for children and adults with disabilities has been used as a form of therapy in the United States for over forty years. However, very little research has been done to find out whether or not THR is effective as a therapy for children with an ASD. This study is being done to see if THR will improve the agitation behaviors, coordination, and communication skills of children and adolescents with an ASD. This study is also being done to find out if the horse is necessary for children and adolescents with an ASD to improve.

This study expands previous preliminary equine-assisted intervention research, including the authors' 10-week Therapeutic horseback riding (THR) intervention pilot, by evaluating the effectiveness of therapeutic horseback riding (THR) on self-regulation, socialization, communication, adaptive, and motor behaviors in children with autism spectrum disorder (ASD). Method: One hundred and twenty-seven participants (ages 6-16 years) were randomized by nonverbal IQ standard scores (< 85 or > 85) to one of two 10-week small groups: THR intervention; or barn activity (BA) control group without horses. Both interventions used similar methods, and the fidelity of the THR intervention was monitored. Participants were evaluated within one month pre- and post-intervention by raters blind to intervention conditions and caregiver questionnaires. Weekly during the intervention, caregivers rated participants' behaviors during the preceding week.

Inclusion Criteria:

• Score ≥ 11 on the irritability and stereotypy subscales of Aberrant Behavior Checklist-Community
• Nonverbal IQ ≥ 40
• Diagnosis of autistic or Asperger's disorder prior to study admission from a psychologist or psychiatrist in the community
• Meets diagnostic cut-off scores for autism spectrum on the Social Communication Questionnaire (SCQ) (> 15) and on the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2)
• Meets DSM-IV-TR criteria for autistic or Asperger's disorder based on diagnostic information gathered for this study from the SCQ, ADOS-2, and Repetitive Behavior Scales-Revised (RBS-R)
• Absence of significant vision, hearing, or motor impairments
• Absence of genetic disorders known to be causative of or potentially resulting in a phenotype similar to autism: Fragile X Syndrome, Landau Kleffner, Rett Syndrome, Childhood Disintegrative Disorder, or tuberous sclerosis, based on screening by clinical staff
• In the event that a family has more than one child diagnosed with autism or Asperger's, only one child per family will be included in the study that meets other study inclusion criteria to maintain independent observation of the participant
• Must have a consistent school-based teacher (vs. a parent who is providing home schooling) willing to complete the ABC-C form twice during the study for each participant, as well as a parent/guardian who is willing to complete the designated outcome parent/guardian report forms during the study

Exclusion Criteria:

• Child has a medical or psychiatric disorder or behavioral issue that would prevent participation
• Child has had no more than 2 hours exposure to EAATs (equine assisted activities and therapies) in the past 6 months and is judged, during the evaluation at Hearts & Horses by the research site coordinator, to not have significant riding experience (an individual with significant riding experience is defined here as one for whom the beginner curriculum would not be appropriately challenging), as the curriculum is designed for beginner riders
• The child has a history of animal abuse or phobia to horses
• Wards of the State