Using Salivary Biomarker Testing of Horse, Rider, and Volunteer to Assess Stress in an Adaptive Riding Intervention for Youth with Anxiety

Purpose: Equine-Assisted Services have demonstrated beneficial impact for children towards reducing stress and anxiety. Researchers have called for an evaluation of animal welfare as relevant to our code of ethics. Historically social science relies heavily on self- or parent-report measures. In 2011, a call in the literature recommended including physiological indicators to assess mechanisms of change in the study of HAI to improve scientific rigor. Collection of salivary samples are a minimally invasive, biopsychosocial measure that accurately depicts stress response levels to an intervention. Both assertions highlight the role animals play in social work and outline the need to bring competencies with care and attention to our animal partners.

Methods: A 10-week adaptive horseback riding protocol was created called “Reining in Anxiety” (RiA), which combined evidence-based practices for childhood anxiety, mainly cognitive-behavioral elements, with progressive horsemanship skills. Results from the pilot with a random sample (N=41) demonstrated significant improvement in anxiety symptoms and emotional self-efficacy.

The goal of the current study is to test the reliability of RiA with youth, and the feasibility of new methods of saliva sampling in synchronous samples from horses, riders, and volunteers (referred to as triad sample) at a Professional Association of Therapeutic Horsemanship, premiere accredited facility. To address the call for inclusion of animal welfare in social science research, the study will test a modified bit for saliva collection in horses. Participants are children with mild to moderate anxiety between the ages of 6-17 measured by the Children’s Global Assessment Scale and Generalized Anxiety Disorder-2. Cortisol, oxytocin, and alpha-amylase are collected from the triad samples before and after sessions 1, 4, 7, and 10. These three analytes are provided to Salimetrics using the gold-standard ELISA assay. Additional study measures include parent-report pre- and post-surveys, child-report surveys and fidelity measures of sessions.

Results: Preliminary testing was conducted with eight horses that are scheduled to be involved in the replication study. Each horse had two samples collected in succession: one using the modified bit, and one from a cheek swab. All eight cheek swab samples were valid for analysis, and 7 of 8 bit samples were valid for analysis. A paired samples analysis of these samples showed that the average volume of saliva collected by the cheek swab (1187.50 µL) was higher than the average volume collected by the bit (587.50 µL). These results support the feasibility of the modified bit as a method to collect triad samples in the replication study.

Implications and Conclusions: These preliminary findings suggest that the bit method is viable to collect saliva, but the apparatus should be adjusted to allow for increased saliva to be collected. The data support the calls to action to: 1. include physiological feedback through saliva sampling; 2. inclusion of animal welfare analysis within human-animal interaction research. This physiological method has the potential to provide insight into if RiA has a directional impact on the concordance of stress between children/riders, volunteers, and horses.