Ropivacaine vs Liposomal Nerve Blocks for Dog Spinal Surgery

Comparing Two Nerve Block Drugs for Spinal Surgery in Dogs

New research directly compared two long-acting local anesthetics for managing pain after major spinal surgery in dogs. A study from Gulf Coast Veterinary Specialists in Houston examined 112 dogs undergoing hemilaminectomy surgery for slipped discs. All dogs received a specialized nerve block called an erector spinae plane (ESP) block, but were randomly assigned to receive either ropivacaine or a newer formulation called liposomal bupivacaine. The goal was to determine if one provided superior pain control in the critical 24 hours after surgery.

No Winner Found in Post-Surgical Pain Control Trial

Shelby Scanlin and Ricardo Salazar led the randomized, blinded study. They administered the ESP block with either ropivacaine or liposomal bupivacaine at a standard dose of 0.4 mL per kilogram of body weight. Liposomal bupivacaine is a sustained-release formulation where the drug is encapsulated in fatty spheres, designed to provide analgesia for up to 72 hours in humans. Ropivacaine is a well-established, long-acting local anesthetic.

Using the validated short-form Glasgow Composite Measure Pain Scale (CMPS-SF), the team assessed pain at multiple points after surgery. The median pain score for both groups was 3 out of 24 at the 1, 4, 6, and 12-hour marks, indicating mild to moderate pain. By 24 hours, scores had dropped to a median of 2. Statistical analysis showed no meaningful difference in pain scores between the two drug groups at any time. “These results indicate there is no significant difference in pain scores,” the authors concluded. This finding is important for veterinary practice, as ropivacaine is typically less expensive than the newer liposomal product.

Anatomical Studies Aim to Improve Neck Surgery Analgesia

Separate research is working to expand safe and effective nerve block options for other complex surgeries. A 2026 cadaveric study published in Frontiers in Veterinary Science by a team from the University of Zaragoza and others established the anatomy for a new block targeting the cranial cervical spine. Led by A. Cañón Pérez, the study described an ultrasound-guided “cranial multifidus cervicis plane block.”

This technique aims to deliver local anesthetic to the nerves supplying the deep muscles and joints at the front of a dog’s neck. Successful blocks in this area could provide targeted pain relief for procedures like cervical disc surgery or neck trauma, reducing the need for higher doses of systemic opioids that can cause sedation, nausea, or constipation. While this was an anatomical study that needs validation in live patients, it represents the ongoing work to refine regional anesthesia, providing more tools for what is known as multimodal pain management.

Pain Peaks Early, Requiring Layered Management

A consistent finding from the hemilaminectomy trial was the pain trajectory. Scores at 1 and 4 hours after surgery were significantly higher than at the 24-hour mark for all dogs, regardless of the drug used. This underscores a fundamental principle of veterinary analgesia: even the most effective single intervention is rarely sufficient for major surgery.

The study protocol itself reflected this. All dogs, in addition to the nerve block, received a postoperative fentanyl infusion for 24 hours. Rescue opioid doses were given if a dog’s heart rate or blood pressure rose during surgery, and ketamine was administered if postoperative pain scores exceeded a set threshold. This protocol highlights that modern pain management is a dynamic process involving pre-emptive nerve blocks, continuous systemic medication, and rescue plans based on objective scoring. A focus solely on one “best” drug misses the broader picture of comprehensive care.

Practical Steps for Pet Owners Facing Surgery

For owners whose dogs require major surgery like a hemilaminectomy, understanding pain management protocols can reduce anxiety. You should expect your veterinary team to use a combination of strategies. A nerve block, similar to the ESP block studied, is a common component for procedures on the trunk or limbs. These blocks are performed under ultrasound guidance after a dog is anesthetized, so they feel nothing during the procedure.

After surgery, pain is assessed regularly using a structured scale. Dogs will typically receive continuous pain medication via an intravenous line initially, followed by oral medications at home. It’s essential to discuss the full plan with your surgeon, including what medications your dog will go home with and how to recognize signs of pain or discomfort. Effective pain management supports faster healing, better mobility, and a smoother recovery, much like quality sleep supports overall cellular health during recovery. While new drugs and techniques are always under investigation, the core principle remains using several complementary methods to keep pain well-controlled.

Conclusion

Recent studies confirm that established anesthetics like ropivacaine remain highly effective for surgical nerve blocks, while anatomical research expands the map for safer, targeted pain relief. The most critical insight for pet owners is that modern veterinary analgesia is a multi-layered strategy, meticulously tailored and adjusted, to ensure comfort through all phases of recovery.

Sources:
https://pubmed.ncbi.nlm.nih.gov/42275766/
https://pubmed.ncbi.nlm.nih.gov/42273263/
https://pubmed.ncbi.nlm.nih.gov/42245458/