Assessing stress in dogs during saliva sampling in socio-psychological research: Preliminary development of animal-friendly practical procedures (2026)

Treder-Rochna, N., Chruściel, E., Gajewska, M. A. et al.

Abstract

This study evaluates the procedure for collecting saliva to measure salivary cortisol levels in dogs, focusing on the potential stress induced by saliva collection in unfamiliar experimental settings. While salivary cortisol measurement is widely regarded as a non-invasive method for assessing stress in dogs, limited data exist on whether the procedure itself may cause discomfort or stress. By addressing this gap, the study aims to explore welfare-related challenges in interdisciplinary research involving non-human subjects and to contribute preliminary insights toward the development of animal-friendly, standardized methodologies. In addition, it sheds light on the organization of an interspecies study involving both human and non-human actors. The study included 19 companion dogs of various breeds, sizes, and temperaments to ensure diverse representation. Saliva samples were collected from dogs during sociological and psychological interviews, with salivary cortisol levels analyzed at the beginning and end of the session. A standardized saliva collection procedure was employed using SalivaBio Children’s Swabs (Salimetrics, State College, PA, USA). The swabs were placed under the dog’s tongue or inside the cheek pouch for approximately two minutes. The procedure was conducted in a controlled environment (a therapy room at the Institute of Psychology) to minimize external stressors. Salivary cortisol concentrations were measured using an enzyme-linked immunosorbent assay (ELISA). Behavioral observations were conducted via video recordings and analyzed by a zoopsychologist using Capra’s Ethogram (2012) as a reference framework. A total of 38 video recordings were analyzed to assess stress-related behaviors. The findings revealed that, while most dogs displayed mild to moderate stress during saliva collection, no extreme stress reactions were observed. Caregiver presence seemed to play a role in reducing visible signs of stress, with emotional support potentially mitigating dogs’ behavioral discomfort. However, these findings are based on qualitative observations and warrant further empirical investigation. Key challenges included variability in saliva production and occasional gum bleeding, which may exclude some samples from the analysis. These factors should be considered when designing future studies. Despite these challenges, salivary cortisol measurement proved to be a reliable and minimally invasive tool for assessing stress, especially when combined with behavioral observations to contextualize physiological data. This study underscores the necessity of standardized protocols that prioritize animal welfare, offering valuable insights to refine research methodologies and deepen our understanding of canine stress responses. Overall, the study proposes a protocol for saliva collection adapted for social science research involving dogs, with an innovative, structured preparatory stage designed to enhance animal comfort and minimize stress associated with the unfamiliar research environment.