Equine-Assisted Therapy in Post-Traumatic-Stress Disorder: A Systematic Review and Meta-Analysis

•EAT has been recently put in the spotlight for the treatment PTSD.•EAT significantly improves post-traumatic stress symptoms.•Major standardization and further research on the long-term effects are needed. Alternative treatments for Post-traumatic-Stress Disorder (PTSD) have attracted attention, especially Equine-Assisted Services (EAS) including psychotherapy and occupational therapy involving horses. In this work, we measured the effectiveness of EAS in PTSD through a meta-analysis. An intensive bibliography search focusing in EAS and PTSD was conducted following the PRISMA recommendations. The search was not restricted by date. For the quantitative analyses, 5 works were selected. They were chosen based on the instrument utilized for the assessment of PTSD symptoms: the PTSD Checklist for DSM-5 (PCL-5). A random effects model was carried out, showing significant results in the reduction of PTSD symptoms. In the qualitative synthesis, 10 studies were included which showed interesting results in the improvement of PTSD symptoms and other variables. In conclusion, EAS are beneficial for post-traumatic symptoms in the short term follow-up period. However, EAS require further research and major standardization.