Bilateral Hemipenectomization Using Local Anesthesia in Invasive Green Iguanas (Iguana iguana) on Grand Cayman Island
American Association of Zoo Veterinarians Conference 2015
Eric Klaphake1, DVM, DACZM, DABVP (Avian), DABVP (Reptile/Amphibian); Matthew Johnston2, VMD, DABVP (Avian); Karen Rosenthal3, DVM, MS
1Cheyenne Mountain Zoo, Colorado Springs, CO, USA; 2College of Veterinary Medicine, Colorado State University, Fort Collins, CO, USA; 3School of Veterinary Medicine, St. Matthew’s University, Seven Mile Beach, Grand Cayman
Fourteen subadult and adult free-ranging male invasive green iguanas (Iguana iguana) were captured via pole-noosing from trees on Grand Cayman Island in November 2014 to evaluate proof of concept of performing bilateral hemipenectomies in field conditions. The iguanas had eyes hooded and were held in dorsal recumbency. Sterile saline was injected caudal to the cloacal opening to completely evert a hemipene. The hemipene base was infused with lidocaine. After two minutes, a hemostat was placed across the entire base of the hemipene, distal to the local block site. A 3-0 monofilament was used to ligate via a transfixation/circumferential suture between the hemostat and local block site. The hemipene stump was cut. The amputation site was cauterized with silver nitrate, then the stump gently replaced into the cloaca. This was repeated with the second hemipene. A one-centimeter hole was punched through the dewlap with the edges cauterized with silver nitrate to assist with visual identification of the iguana upon return to its habitat. One more cloacal hemorrhage assessment was performed, and the iguana was then released. Survival of altered iguanas was visually confirmed for several days post-release. This technique appears to show promise as an ethical, cost-effective, non-lethal, simple method that is able to be performed in the field. Evaluation of effectiveness on curbing population growth is unknown at this time but should be considered as the natural progression to investigate proof of concept further.