Figure 6.11 Gastrotomy in an axolotl (Ambystoma mexicanum): (a) suture of the stomach wall in a single layer with a continuous pattern of absorbable monofilament suture. (b) Recovery of the axolotl after suturing the skin with monofilament suture using a slightly everting continuous pattern.
Source: Photo courtesy: Dr. Marcie Logsdon, Exotics and Wildlife Department, Washington State University.
Minimally Invasive Surgery
Minimal invasive surgery has been described in detail for amphibians (Chai 2015b). Indications are similar to other vertebrate species and include organ biopsy, sex determination, and retrieval of gastrointestinal foreign bodies (Gentz 2007). An oral speculum may be used during gastroscopy to prevent trauma to the endoscope. To visualize the heart, liver, urinary bladder, and gastrointestinal tract via celioscopy, a paramedian incision has been recommended, whereas a lateral approach is preferred to visualize the gonads, adrenal glands, and kidneys (Gentz 2007). Celioscopy should take no more than 10 minutes to minimize anesthetic risks (Chai 2015b). Saline insufflation or carbon dioxide insufflation can be used to improve visualization during celioscopy (Chai 2015a).
Telemetry and Microchip Implantation
Passive integrated transponder devices (PIT tags) have been placed in captive and free‐ranging amphibians. PIT tags are typically surgically implanted intracoelomically in urodela and caecilians, while they can be implanted subcutaneously in anurans (Wright and Whitaker 2001a). In hellbenders, subcutaneous implantation on the dorsal aspect of the tail has been described (Norton et al. 2014). Cosmetic implantation sites include the ventral thigh on either side or deep to the parotid gland in anurans (Wright and Whitaker 2001a). When inserting the microchip subcutaneously, close the insertion site with tissue glue to prevent osmotic imbalance (Norton et al. 2014). For intracoelomic implantation, make a paramedian coelotomy incision rather than inserting the microchip blindly into the coelom to avoid internal organ trauma (Wright and Whitaker 2001a). Some researchers have expressed concerns regarding microchip implantation in free‐ranging amphibians of small size (Funk et al. 2005), but no reference was cited to document adverse effects of microchip implantation. A marking technique using a gun to inject pressurized fluorescent pigment was recommended (Schlaepfer 1998). Alternative marking techniques include subcutaneous visible implant elastomer tags, fluorescent pigments injected with a needle and detected with ultraviolet lights, or toe clipping, but external identification techniques can become illegible (Gibbons and Andrews 2004).
Radiotransmitters may be implanted intracoelomically (Johnson 2006) or placed externally in amphibians (Norton et al. 2014). Due to the risks associated with external radiotransmitters, many researchers opt for intracoelomic implantation. Incise the ventral skin, coelomic muscles, and coelomic lining and insert the radiotransmitter into the coelomic cavity (Norton et al. 2014). Close the muscular layer with polydioxanone suture and the skin layer with nylon. Researchers should consider removing the radiotransmitter at the completion of their study to prevent chronic coelomitis (Norton et al. 2014).
References
1 Aguilar, C. and Gardiner, D.M. (2015). DNA methylation dynamics regulate the formation of a regenerative wound epithelium during Axolotl limb regeneration. PLoS ONE 10: e0134791.
2 Archibald, K.E., Minter, L.J., Dombrowski, D.S. et al. (2015). Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii). Journal of Zoo and Wildlife Medicine 46: 105–112.
3 Bainton, C. and Strichartz, G. (1994). Concentration dependence of lidocaine‐induced irreversible conduction loss in frog nerve. Anesthesiology 81: 657–667.
4 Baitchman, E.J. and Herman, T.A. (2015). Caudata (Urodela). In: Fowler's Zoo and Wild Animal Medicine, 8e (eds. R.E. Miller and M.E. Fowler), 13–19. St. Louis, MO: Elsevier.
5 Braitman, E. and Stetter, M. (2014). Amphibians. In: Zoo Animal and Wildlife Immobilization and Anesthesia, 2e (eds. G. West, D. Heard and N. Caulkett), 303–312. Ames, IO: Wiley Blackwell.
6 Chai, N. (2015a). Anurans. In: Fowler's Zoo and Wild Animal Medicine, 8e (eds. R.E. Miller and M.E. Fowler), 1–12. St. Louis, MO: Elsevier.
7 Chai, N. (2015b). Endoscopy in amphibians. Veterinary Clinics of North America: Exotic Animal Practice 18: 479–491.
8 Chai, N. (2016). Surgery in amphibians. Veterinary Clinics of North America: Exotic Animal Practice 19: 77–95.
9 Clayton, L.A. and Mylniczenko, N.D. (2015). Caecilians. In: Fowler's Zoo and Wild Animal Medicine, 8e (eds. R.E. Miller and M.E. Fowler), 20–26. St. Louis, MO: Elsevier.
10 Diaz Quiroz, J.F., Tsai, E., Coyle, M. et al. (2014). Precise control of miR‐125b levels is required to create a regeneration‐permissive environment after spinal cord injury: a cross‐species comparison between salamander and rat. Disease Models & Mechanisms 7: 601–611.
11 Dombrowski, D.S., Vanderklol, C., and Van Wettere, A.J. (2016). Curative surgical excision of a squamous cell carcinoma associated with the digit of an Amercian bullfrog (Lithobates catesbeianus). Journal of Herpetological Medicine and Surgery 26: 42–45.
12 Felt, S., Papich, M., Howard, A. et al. (2013). Tissue distribution of enrofloxacin in African clawed frogs (Xenopus laevis) after intramuscular and subcutaneous administration. Journal of the American Association for Laboratory Animal Science 52: 186–188.
13 Filoni, S. (2009). Retina and lens regeneration in anuran amphibians. Seminars in Cell & Developmental Biology 20: 528–534.
14 Fleming, G.J. and Isaza, R. (2000). What is your diagnosis? A 4‐cm mass protruding from the dorsal area of the cloaca. Journal of the American Veterinary Medical Association 217: 325–326.
15 Fleming, G.J., Corwin, A., Mccoy, A.J. et al. (2008). Treatment factors influencing the use of recombinant platelet‐derived growth factor (Regranex) for head and lateral line erosion syndrome in ocean surgeonfish (Acanthurus bahianus). Journal of Zoo and Wildlife Medicine 39: 155–160.
16 Forzan, M.J., Vanderstichel, R.V., Ogbuah, C.T. et al. (2012). Blood collection from the facial (maxillary)/musculo‐cutaneous vein in true frogs (family Ranidae). Journal of Wildlife Diseases 48: 176–180.
17 Funk, W.C., Donnelly, M.A., and Lips, K.R. (2005). Alternative views of amphibian toe‐clipping. Nature 433: 193.
18 Gentz, E.J. (2007). Medicine and surgery of amphibians. ILAR Journal 48: 255–259.
19 Gibbons, J.W. and Andrews, K. (2004). PIT taggining: simple technology at its best. BioScience 54: 447–454.
20 Green, S.L. (2010). The Laboratory Xenopus sp. Boca Raton, FL: CRC Press.
21 Gutleb, A.C., Bronkhorst, M., Van Den Berg, J.H. et al. (2001). Latex laboratory‐gloves: an unexpected pitfall in amphibian toxicity assays with tadpoles. Environmental Toxicology and Pharmacology 10: 119–121.
22 Hadfield, C.A. and Whitaker, B.R. (2005). Amphibian emergency medicine and care. Seminars in Avian and Exotic Pet Medicine 14: 79–89.
23 Hedrick, M.S., McNew, K.A., and Crossley, D.A. (2015). Baroreflex function in anurans from different environments. Comparative Biochemistry and Physiology ‐ Part A: Molecular & Integrative Physiology 179: 144–148.
24 Helmer, P. and Whiteside, D. (2005). Amphibian anatomy and physiology. In: Clinical Anatomy and Physiology of Exotic Species: Structure and Function of Mammals, Birds, Reptiles and Amphibians (ed. B. O'Malley), 5–16. Edinburgh, Ireland: Elsevier.
25 Imai, D.M., Nadler, S.A., Brenner, D. et al. (2009). Rhabditid nematode‐associated ophthalmitis and meningoencephalomyelitis in captive Asian horned frogs (Megophrys