Abstract

North Carolina State University's, College of Veterinary Medicine has a student run, non-profit organization for the care of injured wild turtles. The majority of these patients require surgical shell repair. Following this procedure, turtles may take weeks or months to return to normal activity levels and start eating again. This may be a consequence of post-operative pain. Although in mammals opioids are the drugs of choice for post-operative analgesia, this class of drug is reported to be ineffective in reptiles.¹ A nonsteroidal anti-inflammatory, Ketorolac, has been shown to be as effective as morphine sulfate for analgesia in humans and it has a good reputation for the treatment of joint and bone pain.² Like other nonsteroidal anti-inflammatories, Ketorolac's primary side effects involve the gastrointestinal tract, but these occur in less than 3% of humans receiving the drug. To test Ketorolac's effectiveness in shell-repair turtles, a single injection of a dose based upon allometric scaled format, based upon the weight of each turtle is administered.

Eastern box turtles (Terrapene carolina carolina) and yellow bellied sliders (Chrysemys scripta scripta) with relatively minor shell fractures (1 or 2 on a 3 point scale) without other apparent injuries were included in the study. The study design is blinded and turtles are assigned to treatment or control groups by a coin toss. Pain was evaluated using 3 factors, lowering of the heart rate after administration of Ketorolac, the length of time until a turtle returned to feed, and the turtle's return to a "normal" activity level. The definition of a "normal" activity level was based upon observation of wild caught uninjured turtles which were kept in the lab. Each turtle was observed for specific tasks. These tasks included such items as walking, moving their head from side to side, and eating. There were a total of 6 tasks being observed to determine an activity score. Each of these factors was assessed for ten days post-operatively.

To date 3 slider and 2 box turtles have been entered in the study. Due to the randomization of the study, both box turtles have received the drug. Two of the sliders received the drug and one did not. It appears that heart rate may not be a useful parameter because of the high variability from turtle to turtle and temporarily within an individual. However, both the behavior score and return to feed show some promise. In fact the turtles that received Ketorolac started eating on day 5 and day 9 after surgery while the control turtle did not eat for over 14 days following the surgery. Additionally, the activity score was considerably higher in the turtles that received the drug in comparison to the control.

More turtles must be examined before conclusions can be drawn but preliminary clinical experience indicated that Ketorolac is a promising analgesic. The study should be completed by the end of the 1998-1999 turtle season.

Acknowledgments

I would like to thank The Geraldine R. Dodge Foundation for funding this project over the 1997 summer season. Without their support and patience, I would not be able to continue this work. I would also like to thank Dr. Michael Stoskopf for his editorial comments.

References

1.  Mader, Douglass. Reptile Medicine and Surgery. WB Saunders. 1996:241-247.

2.  O'Hara et al. 1987. Ketorolac tromethamine as compared with morphine sulfate for treatment of postoperative pain. Clin Pharmacol Ther 44:556-561.