ANAESTHESIA AND PAIN MANAGEMENT IN COMPANION ANIMALS

In the last decades, pain management has become central to small animal practice. Alleviating pain is not only a professional obligation but also a key contributor to successful case outcomes. Although acute and maladaptive chronic pain management is now an established component of therapy, the development of new drugs, analgesic techniques and non-pharmacological modalities makes this a still evolving facet of small animals clinical practice. Intraperitoneal and intra-articular administration of analgesic drugs are two alternative, simple and low-cost techniques for perioperative pain management in small animal practice. Based on the results obtained in the first study of this PhD dissertation, intraperitoneal administration of local anesthetics provides effective post-operative pain relief in dogs undergoing major abdominal surgeries. Intraperitoneal ropivacaine, a longer lasting local anesthetic, provided an analgesic effect lasting up to 24 hours after the end of surgery. Its duration was longer than that of intraperitoneal lidocaine and this finding results in a decreased postoperative opioids requirement and in a more rapid food intake in recruited dogs. Results of the second study presented in this this PhD dissertation showed that preemptive intra-articular dexmedetomidine, alone or in combination with lidocaine, provided effective intraoperative analgesia in dogs undergoing arthroscopy; treatments also resulted in similar postoperative analgesic effects. In the third and fourth studies we moved to maladaptive chronic pain treatment, describing two new possible therapies for maladaptive chronic pain in dogs: a multimodal pharmacological management involving cannabidiol, a new therapeutic option in dogs affected by osteoarthritis, and the use of radiofrequency, an interventional and non-pharmacological technique, completely new in veterinary medicine. According to the results of our third study, a satisfactory pain and quality of life management was achieved in dogs receiving oral transmucosal cannabidiol oil in addition to a multimodal pharmacological approach for treatment of osteoarthritis-related pain in dogs. Combined with an anti-inflammatory drug, gabapentin and amitriptyline, cannabidiol appears to enhance osteoarthritic pain relief and quality of life improvement. Furthermore, its co-administration results useful in reducing the other administered drugs’ dosage, minimizing the severity and incidence of associated side effects. The high cannabidiol patient tolerability, the easy practicability and the paucity of adverse effects of oral transmucosal route of administration may represent potential benefits for long-term therapy. In the fourth study we focused on radiofrequency, whose long-term efficacy has been previously evaluated in a small group of dogs affected by maladaptive chronic pain. Although this study is an ongoing project and in the present form includes a small number of patients, in accordance with the obtained preliminary results, it seems that radiofrequency is an effective procedure that do not result in the development of serious adverse effects in dogs suffering of maladaptive chronic pain. In conclusion, this dissertation includes studies of different nature, involving different analgesic techniques for management of different types of pain in dogs, but the common thread is represented by the attempt to find new treatment options, in order to promote a proactive, preemptive and multimodal pain management in companion animals. The rationale behind this attempt is that using new pharmacological and non-pharmacological techniques, targeting multiple sites in pain pathways, minimize the potential for side effects associated with any single technique and provide a more effective pain management. Pain alleviation, and therefore animals welfare, is an ethical and medical duty and all the new techniques to reduce pain, stress and anxiety should be encouraged.