Current Advances in Assessment of Dog’s Emotions, Facial Expressions, and Their Use for Clinical Recognition of Pain
Daniel Mota-Rojas,
Míriam Marcet-Rius,
Asahi Ogi,
Ismael Hernández-Ávalos,
Chiara Mariti,
Julio Martínez-Burnes,
Patricia Mora-Medina,
Alejandro Casas,
Adriana Domínguez,
Brenda Reyes,
Angelo Gazzano
Affiliations
Daniel Mota-Rojas
Neurophysiology of Pain, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico
Míriam Marcet-Rius
Animal Behaviour and Welfare Department, IRSEA (Research Institute in Semiochemistry and Applied Ethology), Quartier Salignan, 84400 Apt, France
Asahi Ogi
Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy
Ismael Hernández-Ávalos
Department of Biological Sciences, Clinical Pharmacology and Veterinary Anaesthesia, FESC, Universidad Nacional Autónoma de México (UNAM), Cuautitlán Izcalli 54714, Mexico
Chiara Mariti
Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy
Julio Martínez-Burnes
Animal Health Group, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Victoria City 87000, Mexico
Patricia Mora-Medina
Department of Livestock Science, FESC, Universidad Nacional Autónoma de México (UNAM), Cuautitlán Izcalli 54714, Mexico
Alejandro Casas
Neurophysiology of Pain, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico
Adriana Domínguez
Neurophysiology of Pain, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico
Brenda Reyes
Neurophysiology of Pain, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico
Angelo Gazzano
Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy
Animals’ facial expressions are involuntary responses that serve to communicate the emotions that individuals feel. Due to their close co-existence with humans, broad attention has been given to identifying these expressions in certain species, especially dogs. This review aims to analyze and discuss the advances in identifying the facial expressions of domestic dogs and their clinical utility in recognizing pain as a method to improve daily practice and, in an accessible and effective way, assess the health outcome of dogs. This study focuses on aspects related to the anatomy and physiology of facial expressions in dogs, their emotions, and evaluations of their eyebrows, eyes, lips, and ear positions as changes that reflect pain or nociception. In this regard, research has found that dogs have anatomical configurations that allow them to generate changes in their expressions that similar canids—wolves, for example—cannot produce. Additionally, dogs can perceive emotions similar to those of their human tutors due to close human-animal interaction. This phenomenon—called “emotional contagion”—is triggered precisely by the dog’s capacity to identify their owners’ gestures and then react by emitting responses with either similar or opposed expressions that correspond to positive or negative stimuli, respectively. In conclusion, facial expressions are essential to maintaining social interaction between dogs and other species, as in their bond with humans. Moreover, this provides valuable information on emotions and the perception of pain, so in dogs, they can serve as valuable elements for recognizing and evaluating pain in clinical settings.