Assessment of pain-related emotions in dogs by three observer groups using a qualitative method and a pain scale

Pain is an unpleasant sensory and emotional experience. In contrast with humans, who can usually communicate their emotional states, animals do not have any verbal means of communication [1]. Thus, the capability of human observers to appreciate animal emotions is essential. Free Choice Profiling (FCP) methodology was used in qualitative behavioral assessment (QBA) in many species [2, 3, 4, 5, 6, 7]. QBA investigates the emotional status of the animals and it does not rely on what an animal does, but on how it does what it does. FCP approach allows observers to generate their own vocabulary to describe emotional expression of observed animals, enhancing the active interpretation of animals rather than providing them with a fixed list of terms [2]. To our knowledge, FCP methodology has been never applied to pain assessment. This study aims to investigate the ability of three observer groups to blindly recognize pain-related emotions in 20 dogs (10 “in pain” dogs and 10 “healthy” dogs) using FCP methodology. The observers (10 dog owners, 10 veterinary medical students and 10 veterinarians) applied FCP watching twice the footages of the dogs. In video session 3, students and veterinarians assessed dogs’ pain using Glasgow Composite Pain Scale-Short Form (GCPS-SF) [8]. FCP data were analyzed using Generalized Procrustes Analysis (GPA): a good agreement was achieved by each observer group, confirming the applicability of this methodology in dogs [5]. “Healthy” dogs were mainly described as tranquillo (“quiet”) and vivace (“lively”), while the majority of “in pain” dogs were considered dolorante (“sore/in pain”) and sofferente (“suffering”). Pain-related dimension of the consensus profile was different among groups as well as the capability to differentiate between “healthy” and “in pain” dogs. Thus, observers’ cultural background and personal experience could affect QBA in suffering dogs. Moreover, a high correlation was found between FCP data and GCPS-SF scores. The results of this study show that qualitative methods such as FCP could be used in association with semi-quantitative methods to investigate the effect of pain on animal emotional expression.