Development of a Cutaneous Wound Healing Model for Evaluation of Platelet-Derived Growth Factor (Regranex®) in the Bearded Dragon (Pogona vitticeps)
Krista A. Keller1, DVM; Joanne Paul-Murphy2, DVM, DACZM; E.P. Scott Weber III2, VMD, MSc; Philip H. Kass3, DVM, PhD, Dipl ACVPM; David Sanchez Migallon-Guzman2, LV, MS, DECZM (Avian), DACZM; Christopher J. Murphy4, DVM, PhD, DACVO
1William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA, USA; 2Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, USA; 3Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA; 4Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
Abstract
Wounds in reptiles are a common cause for presentation to a veterinarian;2,4 however, published information regarding therapy for wound healing is limited.1,5 A cutaneous wound healing model with bilateral circular wounds over the dorsal scapular region was developed in the bearded dragon utilizing the splinted wound healing model developed in mice.3 A treatment group (n=5) was administered a topical synthetic platelet-derived growth factor, becaplermin (Regranex®, Healthpoint Biotherapeutics, Fort Worth, TX, USA), on one wound and vehicle (methylcellulose) on the other. A control group (n=5) received vehicle on one wound and saline on the other. The wounds were imaged using a Nikon digital SLR fitted with a macro lens at each treatment session. Wounds were treated daily for days 0–17, then every second day until 80% wound healing was achieved. Image analysis software was used to calculate wound area by manually tracing the advancing epithelial front as well as the border of the dermal wound margin (to quantify wound contraction). Day 0 and day 15 wound areas were compared to calculate percentage wound closure. A Mann-Whitney test was used to compare each of the four treatments. Becaplermin significantly accelerated (p<0.016) wound closure compared to vehicle. No significant differences were found between other treatment groups. This wound healing model may be used to evaluate other topical products and reptile wound healing physiology.
Acknowledgments
This project was supported by the Center for Companion Animal Health, School of Veterinary Medicine, University of California, Davis and the authors are grateful for the generous donation of product from Healthpoint Biotherapeutics.
Literature Cited
1. Adkesson, M.J., E.K. Travis, M.A. Weber, J.P. Kirby, and R.E. Junge. 2007. Vacuum-assisted closure for treatment of a deep shell abscess and osteomyelitis in a tortoise. J Am Vet Med Assoc. 231:1249–1254.
2. Cooper, J.E. Dermatology. In: Reptile Medicine and Surgery. 2nd Ed. Ed: Douglas Mader. Saunders-Elsevier. 196–216.
3. Fang, R.C. and T.A. Mustoe. 2008. Animal models of wound healing: utility in transgenic mice. J Biomater Sci Polymer Edn. 19: 989–1005.
4. Mitchell, M.A. and O. Diaz-Figueroa. 2004. Wound management in reptiles. Vet Clin Exot Anim. 7: 123–140.
5. Smith, D.A., I.K. Barker, and O.B. Allen. 1988. The effect of certain topical medications on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis). Can J Vet Res. 52: 129–133.