Skip to main content

ORIGINAL RESEARCH article

Front. Vet. Sci.
Sec. Anesthesiology and Animal Pain Management
Volume 12 - 2025 | doi: 10.3389/fvets.2025.1520172
This article is part of the Research Topic Exploring Anesthetic Risk: Challenges and Solutions in Veterinary Medicine View all 6 articles

RH: Hydromorphone as Analgesic for Alligators Analgesic Efficacy of Hydromorphone in American Alligators (Alligator mississippiensis)

Provisionally accepted
Scott E Henke Scott E Henke 1*David B Wester David B Wester 1Cord Eversole Cord Eversole 2Javier O Huerta Javier O Huerta 1Clay D Hilton Clay D Hilton 1Kurt K Sladky Kurt K Sladky 3
  • 1 Caesar Kleberg Wildlife Research Institute, College of Agriculture and Natural Resources, Texas A&M University Kingsville, Kingsville, United States
  • 2 Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University, Nacogdoches, Texas, United States
  • 3 Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States

The final, formatted version of the article will be published soon.

    Background: American alligators (Alligator mississippiensis) are maintained in zoos, aquaria, and farms for educational, research, and production purposes. The standard of veterinary medical care and welfare for captive reptiles requires managing pain and discomfort under conditions deemed painful in mammals. While analgesic efficacy and pharmacokinetic data for several reptile species are published, data with respect to analgesic efficacy in crocodilians are clearly lacking.The objective of this study was to determine the analgesic efficacy of hydromorphone in alligators.Methods: Female American alligators (N = 9; 57 months of age) were exposed to mechanical noxious stimuli at multiple anatomic sites using von Frey filaments ranging in size from 1.65 -6.65 grams-force, and their behavioral reactions recorded. In order to evaluate analgesic efficacy, hydromorphone (0.5 mg/kg SC) was administered in the axillary region to the same alligators and the mechanical noxious stimuli were repeated and behaviors recorded.Results: Administration of hydromorphone contributed to a range from 62 -92% reduced avoidance reactions to mechanical noxious stimuli for two anatomic sites (i.e., naris and lateral mandible, respectively).Alligators did not appear to experience clinically relevant respiratory depression, hypothermia, or other adverse reactions. Therefore, hydromorphone shows promise as an analgesic option to be administered under painful conditions in American alligators.

    Keywords: Alligator mississippiensis, American Alligator, Analgesia, Hydromorphone, Nociception, von Frey, Pain Management, reptile

    Received: 30 Oct 2024; Accepted: 22 Jan 2025.

    Copyright: © 2025 Henke, Wester, Eversole, Huerta, Hilton and Sladky. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Scott E Henke, Caesar Kleberg Wildlife Research Institute, College of Agriculture and Natural Resources, Texas A&M University Kingsville, Kingsville, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.