A multimodal opioid‐sparing anaesthetic approach in a cat forelimb amputation, utilising perioperative magnesium sulphate administration

Abstract An 8‐year‐old, male, neutered cat underwent forelimb amputation to manage a fibrosarcoma. Utilising a multimodal opioid‐sparing approach, dexmedetomidine, midazolam and buprenorphine were administered for premedication, while induction and maintenance of anaesthesia were achieved with propofol. Additionally, a constant rate of infusion of ketamine and magnesium sulphate, regional ropivacaine infusion through a wound infusion catheter, meloxicam and pregabalin were administered throughout the perioperative period. Postoperative pain was assessed with Unesp–Botucatu Feline Pain Scale and Feline Grimace Scale, while serial measurements of serum magnesium concentrations were carried out up to 36 hours postoperatively. No rescue analgesia was required during the intraoperative or postoperative period, and the cat was discharged on the fourth postoperative day. After 18 months, the cat remains asymptomatic without signs of cancer recurrence. This opioid‐sparing approach contributed to intraoperative haemodynamic stability and an optimal analgesic outcome, despite minimum opioid utilisation. Furthermore, no serious adverse effects, related to magnesium perioperative administration, were observed.