Physiological and Facial Expression Data of Pantaneiro Horses During Social Enrichment and Short-Term Stress

This dataset contains physiological and facial expression data collected from eleven Pantaneiro horses during restraint in stock under two different social conditions: Social Noncontact Environmental Enrichment (SNE) and Social Isolation (SI). The study aimed to evaluate the effectiveness of SNE in promoting social buffering and to characterize the horses’ emotional states using combined physiological and behavioral indicators. A crossover design was implemented with two treatments: SNE (presence of a conspecific without physical contact) and SI (absence of a conspecific), each lasting 24 minutes. The dataset includes: Physiological parameters: heart rate, heart rate variability (HRV), respiratory rate, ocular temperature (infrared thermography), and auricular temperature (infrared thermometer). Facial expression data: coded using the Equine Facial Action Coding System (EquiFACS), including Action Units (AUs) and Action Descriptors (ADs/EADs) such as nostril dilator (AD38), inner brow raiser (AU101), upper eyelid raiser (AU5), eye white increase (AD1), ears forward (EAD101), and ears back (EAD104). Time series and summary values were recorded throughout the restraint period for both treatments. Data are organized in CSV and/or Excel format, with comprehensive variable definitions and metadata provided. This dataset can support further research in equine behavioral physiology, environmental enrichment strategies, and machine learning applications related to emotional state recognition in horses. All procedures were approved by the relevant animal ethics committee.