Development of an Avian Brachial Plexus Nerve Block Technique for Perioperative Analgesia Using Mallard Ducks
American Association of Zoo Veterinarians Conference 2007

Deena Brenner1,4, DVM; R. Scott Larsen1,2, DVM, MS, DACZM; Raymund F. Wack1,2, DVM, MS, DACZM; Peter J. Dickinson1,3, BVSc, PhD, DACVIM (Neurology); Peter Pascoe1,3, BVSc, PhD, DACVA, DECVA; D. Colette Williams1,3, BS

1Veterinary Medical Teaching Hospital, University of California, Davis, CA, USA; 2Department of Medicine and Epidemiology, University of California, Davis, CA, USA; 3Department of Surgical and Radiological Sciences, University of California, Davis, CA, USA; 4Zoological Society of San Diego, San Diego Zoo, San Diego, CA, USA


This investigation was conducted to develop a brachial plexus nerve block technique for perioperative analgesia in birds. Research on avian regional anesthesia is limited.2,4-6 A pilot study determined the feasibility of recording somatosensory evoked potentials (SSEP) for use in measuring the efficacy of the nerve blockade by testing the integrity of the brachial plexus.1,3 Eight adult female mallard ducks were anesthetized with isoflurane and used in several local anesthetic trials administering bupivacaine (2 mg/kg, 8 mg/kg) and lidocaine (15 mg/kg)/epinephrine (3.8 µg/kg) perineurally with a saline control treatment. Both dorsal and ventral approaches to the brachial plexus were evaluated, and a nerve stimulator was used to increase accuracy of administration. Sensory nerve conduction velocities (SNCV) for radial and ulnar nerves and cord dorsum potentials (CDP) were recorded prior to injection and at 5, 30, and 60 minutes post injection of local anesthetic or saline. For 24 h post injection, birds were intermittently monitored for the presence of a wing droop and decreased motor function. Surgical dissection and transection of the brachial plexus in one duck caused complete elimination of the CDP, which validated electrodiagnostic results.

Results were highly variable for all techniques. No technique consistently eliminated CDP or resulted in consistent wing droops. This may indicate that the treatment, dose, concentration, or volume of local anesthetic was ineffective in producing local analgesia. It is also possible that the methods used to assess loss of pain perception were not sensitive enough to assess the effects of the local anesthetic.


Funding for this research was provided by a grant from the Center for Companion Animal Health, University of California, Davis, Veterinary Medical Teaching Hospital.

Literature Cited

1.  Cuddon P.A., A.J. Delauche, and J.M. Hutchison. 1999. Assessment of dorsal nerve root and spinal cord dorsal horn function in clinically normal dogs by determination of cord dorsum potentials. Am. J. Vet. Res. 60:222–226.

2.  Gentle, M.J., P.M. Hocking, R. Bernard, and L.N. Dunn. 1999. Evaluation of intraarticular opioid analgesia for the relief of articular pain in the domestic fowl. Pharm. Biochem. Behav. 63:339–343.

3.  Holliday, T.A. 1992. Electrodiagnostic examination: Somatosensory evoked potentials and electromyography. Vet. Clin. North Am. 22:833–57.

4.  Hocking, P.M., M. J. Gentle, R. Bernard, and L.N. Dunn. 1997. Evaluation of a protocol for determining the effectiveness of pretreatment with local analgesics for reducing experimentally induced articular pain in domestic fowl. Res. Vet. Sci. 63: 263–267.

5.  Machin, K.L. and A. Livingston. 2001. Plasma bupivacaine levels in mallard ducks (Anas platyrhynchos) following a single subcutaneous dose. Proc. Am. Assoc. Zoo Vet. Pp.159–163.

6.  Mulcahy, D.M., P. Tuomi, R.S. Larsen, R.S.,2003. Differential mortality of male spectacled eiders (Somateria fischeri) and king eiders (Somateria spectabilis) subsequent to anesthesia with propofol, bupivacaine, and ketoprofen. J. Avian Med. Surg. 17:117–123.


Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Deena Brenner, DVM
Veterinary Medical Teaching Hospital
University of California
Davis, CA, USA

MAIN : All : Avian Brachial Plexus Nerve Block for Mallards
Powered By VIN