Dados do Trabalho

Título

FACIAL EXPRESSIONS OF ACUTE PAIN IN JAPANESE MACAQUES: DEVELOPMENT OF AN ASSESSMENT TOOL

Resumo

Changes in facial expression provide a potential way to assess emotion in mammals in both the wild and laboratory setting. Quite apart from an ethical imperative, in a research context it is also important to know that animals are not suffering in order to gather valid data. Here we describe a method to assess pain in Japanese macaques (Macaca fuscata) by observing and quantifying changes in facial expressions using a morphometric approach. Facial images were captured from adult healthy female macaques (n=8) undergoing laparotomy. Video recording was performed with the macaques undisturbed in their cages at least one day before and 1 day after surgery, prior to rescue analgesia. Screenshots from the pre- and post-surgical periods were taken from the videos and selected for analysis on the basis of their appropriate facial orientation to the camera. ImageJ was then used to annotate the face pictures with 42 landmarks related to specific points selected for their relationship to key areas affected by the facial musculature. The images were then compared at the level of individual subject before being pooled (total: 76 images “no pain”; 52 “pain”, sample size varied between subjects). There were consistent changes in the faces of macaques which suggest that pain is associated with tightening of the muzzle, as has been observed in other species. Also, apparent raising of the hairline probably due to piloerection. This work potentially offers an effective complement for existing ways to train others in the evaluation of pain and welfare in captive primates, using data generated as part of their use in other research procedures.

Financiamento

Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT)
Leading Graduate Program in Primatology and Wildlife Science, Kyoto University (PWS)

Palavras-chave

geometric morphometrics; emotion; macaca fuscata