Recognition and management of pain and suffering in research studies involving nonhuman Primates

Expertise and genuine consideration for animal welfare are essential to enable refinement of experimental procedures, aim- ing to prevent or minimize pain and suffering. Our main goal was to define and apply a system to prevent, recognize, and manage suffering during the 3 main phases of transplantation surgery: preoperative, intraoperative, and postoperative phases. In the perioperative period, the improvement of safety and ef- ficacy of anesthesia and analgesia are critical aspects. Aiming to refine the procedure in our primate models, we implement- ed adjustment and refinement in the anesthetic and analgesic protocol. Indeed, a more effective management, a faster recov- ery, and a positive impact on animal welfare were obtained by modifying dosages of drugs administered, whilst guaranteeing the maintenance of an optimal depth of anesthesia and anal- gesia. Considering the postoperative phase, to recognize and manage pain and/or suffering eventually occurring, an evalu- ation system has been implemented, relying on the following aspects: 1) continuous clinical monitoring, ensuring the best possible approach for the prompt evaluation of the animal con- ditions, thus minimizing the risk of mistake or underestimation of clinical signs, 2) continuous laboratory monitoring, allowing an early recognition of any altered physiologic parameter, and 3) definition of specific assessment criteria, with regard to the termination of experimental procedures and consequent eu- thanasia (humane endpoint). This assessment system, based on a combined analysis of both quantitative (measurable) and qualitative (observable) elements, had useful, satisfactory, and reproducible results. We believe that our approach resulted in a reduction of animal suffering without any negative impact on scientific results.