Peer-reviewed veterinary case report
Dog treated for side effects after accidental spinal morphine
By Fisher, Hannah M & Khenissi, Latifa·Published in Veterinary anaesthesia and analgesia·2025·University of Bristol, United Kingdom·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Management of adverse effects after inadvertent intrathecal injection of morphine in a dog undergoing thoracotomy.
- Species:
- dog
Plain-English summary
A 33-kg adult Labrador Retriever was brought in for a collapsed lung and underwent surgery. During the procedure, an accidental injection of morphine into the spinal area caused muscle twitching and prevented the dog from breathing on its own afterward. The veterinary team tried several treatments to help the dog breathe again, but it was only after giving butorphanol, a medication that counteracts morphine, that the dog started to recover. After a few days of monitoring and treatment, the dog was discharged and showed no lasting issues.
People also search for: dog breathing problems after surgery · Labrador Retriever morphine side effects · how to treat dog anesthesia complications
Abstract
A 33-kg adult Labrador Retriever dog presented for investigation of pneumothorax. A computed tomography scan confirmed the diagnosis, and right lateral thoracotomy and lung lobectomy were performed under general anaesthesia. During surgery, anaesthesia was maintained with a propofol constant-rate intravenous (IV) infusion (premedication with methadone and dexmedetomidine) and IV atracurium was given to facilitate surgery. A lumbosacral epidural injection of preservative-free morphine (0.3 mg kgdiluted to 6.6 mL with sterile saline) was performed. Using a spinal needle, the 'hanging drop' method of detecting the epidural space was attempted but the saline drop was not aspirated, and cerebrospinal fluid entered the needle hub, indicating inadvertent dural puncture. The needle was partially withdrawn and a lack of resistance to injection confirmed before injection of morphine. Following injection, myoclonus of the tail was observed throughout surgery, continuing after atracurium administration. Following surgery, the propofol infusion was reduced from 0.3 to 0.1 mg kgminuteto encourage spontaneous ventilation after confirmation of neuromuscular function. Spontaneous ventilation, swallow and palpebral reflexes did not return. The following treatments were unsuccessful in eliciting spontaneous ventilation: allowing end-tidal COto increase [up to 60 mmHg (8 kPa)], reducing inspired oxygen fraction to 0.4, injection of neostigmine and glycopyrrolate, and stopping propofol delivery. Three doses of butorphanol (each 0.5 mg kgIV) were given 30 minutes apart to antagonize the effects of morphine as it was suspected that inadvertent intrathecal injection had been performed. Butorphanol administration was associated with return of spontaneous ventilation, palpebral and swallow reflexes, and full recovery from anaesthesia. Continuous rate infusions of butorphanol and dexmedetomidine were used for 12 hours to treat any residual respiratory depression and provide sedation to manage continued myoclonus. Myoclonus resolved within 24 hours. The dog was discharged 3 days later and suffered no ongoing adverse effects.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/40059012/