Heart rate variability spectral analysis for monitoring automatic activation in a donkey involved in animal-assisted-therapy: a single subject design during animal-assisted-therapy sessions

Background: Only a limited number of studies have investigated objective indicators to assess donkey welfare during Animal-Assisted Services. Objective: The present research follows a single-subject design and its objective is to evaluate the neurovegetative indicators of the well-being of a donkey through spectral analysis of the R-R signal in the frequency domain. Methods: The experimental protocol of the Animal-Assisted Therapy project involved one donkey, previously selected through behavioral protocol evaluation, and ten patients with a diagnosis of paranoid schizophrenia. Spectral analysis of the R-R signal in the frequency domain was performed, providing objective data on the activity of the sympathetic and parasympathetic nervous systems of the donkey (before, during, and after the sessions). Results: The significance of the variations, both statistically significant and not, supports the hypothesis that the affiliative human–donkey interaction within the context of AAS is associated with modifications in the neurovegetative components of the donkey involved in AAT. Conclusions: These findings highlight the importance of objective and non-invasive monitoring tools to detect early signs of discomfort in donkeys involved in AAT, supporting the development of selection and management strategies that safeguard animal welfare.