In daily clinical practice, properly assessing and effectively treating pain in animals is one of the most important but also challenging tasks of a veterinarian. This applies to the general practioner as much as to the large animal specialist treating orthopedic, maxillo-facial, oro-dental, thoracic, gastro-intestinal, or uro-genital diseases.

Effective treatment of forelimb pain in horses is complicated, not only because responses to injuries vary between individual animals, but also because horses put a high load on the forelimbs for most of the day (1/3 of their body weight on each forelimb). Therefore, if a serious injury occurs in one of their forelimbs or the animals undergo major orthopedic surgery in one forelimb, they are predisposed to overloading the contralateral limb, which can undergo devastating disease processes such as laminitis. Thus, pain relief is an important aspect in equine orthopedic care as it is in many other diseases because it significantly decreases the physiological stress of the animal and reduces perioperative complications.

Although the systemic administration of analgesic agents constitutes the predominant analgesic therapy in equine veterinary practice, knowledge of the pathophysiological processes leading to acute onset of pain followed by primary and then especially secondary hyperalgesia suggests that loco-regional anesthesia and analgesia may plays a key role in the perioperative management of patients with severe and / or persistent musculoskeletal pain. Effective pain therapy is best achieved by applying multimodal analgesia. This concept involves the combination of drugs exhibiting different mechanisms of actions and that target different sites within the nociceptive signaling system and that also integrates techniques of loco-regional anesthesia and analgesia.

The main lines of research we focused on are:

• Evaluation of composite pain scales for accurate pain assessment in horses.
• The development of a new technique using continuous perineural block of the palmar nerves to relieve pain in the foot and in the most distal portion of the equine forelimb.
• The development of a new technique using continuous perineural block of the ulnar and median nerves to relieve pain in the distal equine forelimb.
• Evaluation of sensory function tests for assessment of successful perineural nerve blocks in the horse.

• Driessen B, Orsini JA, Zarucco L “Continuous perineural block: a new technique for pain relief in the distal equine forelimb”. Morris Animal Foundation, Project No.: D05EQ-024

• Driessen B, Zarucco L (2017) Ch.33 Analgesia. In: Equine Laminitis. Eds Belknap J,K. Geor R.J. Wiley-Blackwell, Ames, IA / ISBN: 978-1-119-94471-3 pp 291-305.
• Driessen B, Zarucco L (2014) Treatment of acute and chronic pain in horses. In Pain Management in Veterinary Practice. Eds Egger C, Doherty TJ, Wiley-Blackwell, Ames, IA; ISBN: 978-0-8138-1224-3 pp 323-348.
• Seco O, Zarucco L, and Campoy L (2013) Ultrasound-guided Peripheral Nerve Blocks In Small Animal Regional Anesthesia and Analgesia, Eds Campoy L, Read M, Wiley-Blackwell ISBN-13: 9780813819945 pp 304.
• Zarucco L, Driessen B, Scandella M, Cozzi F, Cantile C (2010) Sensory nerve conduction and nociception in the equine lower forelimb during perineural bupivacaine infusion along the palmar nerves. Can J Vet Res: 74 (4): 305–313.
• Driessen B, Bauquier SH, Zarucco L (2010) Neuropathic Pain Management in Chronic Laminitis. Vet Clin North Am Equine Pract: 26 (2): 315-337.
• Zarucco L, Scandella M, Seco O, Driessen B (2008) Ultrasound-guided technique for continuous ulnar and median nerve blockade in the horse. Abstracts of the American College of Veterinary Surgeons – Annual Symposium, San Diego, CA, pg 34, October 23-25 2008; Vet. Surg. 37 (6) pg E34.
• Driessen B, Scandella M, Zarucco L (2008) Development of a technique for continuous perineural blockade of the palmar nerves in the distal equine thoracic limb. Vet Anaesth Analg: 35 (5) 432–448.
• Zarucco L, Driessen B, Scandella M, Seco O, Cozzi F, Orsini JA (2007) Continuous perineural block of the palmar nerves: A new technique for pain relief in the distal equine forelimb. Clin Tech Equine Pract 6:154-16418.
• Driessen B, Zarucco L (2007) Pain – From Diagnosis to Effective Treatment. Clin Tech Equine Pract 6:126-134.
• Zarucco L, Driessen B (2007) Leading Edge: Continuous Peripheral Nerve Block: A Novel Technique. Compend Equine 12:310-317.

• Prof. Bernd Driessen - University of Pennsylvania, New Bolton Center, Pennsylvania, USA
• Dr. Massimiliano Scandella
• Prof. Olga Seco - University of Pennsylvania, New Bolton Center, Pennsylvania, USA