Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Turtle and Tortoise Shell Repair

Melissa Kaplan, 1995


This is an overview of the process used to repair chelonian shells that have been fractured or damaged by infection; there is another document that covers the treatment of shell rot. This is not intended to be a "do-it-yourself" manual but more what you should expect when you take such a turtle or tortoise to an experienced veterinarian for treatment. Remember that the shell serves the same purpose as skin: it protects the interior of body. If skin, or shell, is penetrated, that gives access to bacteria, fungal spores and parasites. The broken shell must be treated as if it were lacerated skin: the tissue and body cavity must be treated first before the shell is closed up.

This first section is a summary of the procedures outlined by Fredric L. Frye in his Reptile Care (TFH Publications):

Repair fractured or surgically invaded plastron and carapace (first cleaned with several applications of ether or acetone and air dried) with single or multiple layers of sterilized fiberglass cloth impregnated with freshly prepared, rapid-polymerizing epoxy resin, and topped with several coats, allowing each to dry before the next coat is applied. (Cut and autoclave round pieces which will overlap the defect by 1.5-3 cm; square ones tend to unravel at the edges.) To insure good chemical bonding is achieved, the dried rapid dry epoxy should be lightly sanded and wiped down with diethyl ether or acetone before the next coat is applied In aquatic or semi-aquatic turtles, a top coat of slower polymerizing boat-repair resin should be applied a day or two after the patch.

Epoxy is applied to the periphery of the defect - not the edges and never inside the defect or cavity...if it gets on the edge of the bony plate it may impede bone healing.

The first patch is worked in to the ring of epoxy. A light coat of resin is applied to the center of the patch enough to just coat and get worked into it -- not saturate through into the coelomic cavity. You will know you have enough worked in when the cloth becomes transparent and the weave sort of disappears. The patches must be completely water- and airtight to prevent invasion by any microorganisms. Generally two layers, plus the top coat, is enough to complete such repairs.

The two-part epoxy components are used in a 1:1 ratio, the time for polymerization is about 3-5 minutes. The resin loses its tackiness and hardens in another 4-5 minutes.

Before placing that chelonian back in its enclosure, spraying the patch with a vegetable oil spray will help prevent substrata from sticking to the fresh patch, especially on ventral patches.

Several sources (not specified) have described the use of cold-curing dental acrylic plastic. Per Frye, regardless of the type of resin used, a laminating layer of the impregnated fiberglass cloth should be used to reduce wear and tear, abrasion, etc.

In most case, Frye continues, the patch should be left in place for a year or two, during which time new bone will regenerate across the gap. If the chelonian is a rapidly growing juvenile, some of the patch will have to be removed to allow the shell to expand unimpeded. Patches may be left in place permanently on adult (fully grown) chelonians) For information on how to do this, see Frye's Reptile Care, chap 13.

If shell has been fractured traumatically, the edges should be debrided and any depressed fragments elevated and returned to proper location. If the fracture is less than 3 cm in diameter, the devascularized bone fragments may be removed. If the gap is very large or pieces are missing, the defect can still be closed with the resin-impregnated fiberglass; while new bone may never fully bridge the gap, it should regenerate to some extent and generally does not interfere with the chelonian's physiologic function.

When grafting bone fragments together, epoxy them first to the patch, and allow the patched pieces to dry before the patch is attached to the edges of the defect.

Occasionally, wiring and plating of severely crushed shells may be done to repair massive trauma, but if there is evidence of paralysis or posterior limb paresis, or both, the prognosis is dim, and euthanasia should be considered.

Other references:

Zeman, W. Z., et al. 1967 describes this process for a box turtle in Repair of the carapace of box turtle using polyester resin. Lab Anim Care 17:424-425

Harwell G. 1989. Repair of Injuries to the chelonian plastron and carapace. In Current Veterinary Therapy, Vol X, pp 789-791.

Heinrich G, and Heinrich D. 1986. A technique for the repair of chelonian shell fractures with a historical review of shell fracture repair. Proc Nat Wildlife Rehab Assoc, pp 1-18.

Doug Mader also wrote on this subject in a early issue of the Journal of Small Exotic Animal Medicine (1990-1991).

This paper is from Katherine T. Belisle, DVM, Wildlife Rehabilitation Clinic, University of Minnesota, St. Paul, MN 55108:

The shell of a turtle or tortoise is composed of an upper dome-shaped piece called the carapace and a lower plate called the plastron. These two are joined together by bony bridges. In most species, except for the soft-shelled turtles, the carapace is composed of bony plates overlaid by hard dermal plates. The most obvious function of the turtle shell is to provide the animal with a protective fortress. Some species, box turtles in particular, have a hinged shell which allows even greater protection. Shells of turtles and tortoises grow larger as the anima matures. This fact will become very important when we consider how to repair a damaged shell.

Shells are injured most often when these animals are run over by cars while crossing the road. They may also be damaged by attacks from dogs or wildlife, lawn mowers, or even surgery. The location of the shell damage and the type of wound will determine best how to repair the defect.

Physical Exam
Because turtle shells are so protective it takes a great deal of force to crush one. This means the turtles you'll encounter with damaged shells will have been under some degree of stress and may be in a critical condition when they arrive at your doorstep. The most important first step is to stabilize the animal, the details of which are beyond the scope of this workshop. The repair of the shell can in most cases be postponed until the animal is able to withstand the additional stress.

At this point, the wound should be carefully inspected for damage to internal structures. You may need the assistance of a veterinarian to determine the possibility of repair or if euthanasia is the best alternative. No repair of a turtle shell should be done on an animal that is paralyzed. Physical exam should include an assessment of the neurological function to both the front and rear legs. This is best accomplished by pinching the toes strongly and watching for a response. A proper response would include a move away from the source of pain or a turn of the head to look at the source of pain. A simple withdrawal of the leg is not sufficient to consider neural function to be intact. Another means of assessing function swim and note the movement of all four limbs. Be careful not to allow water to seep into an open would. If limb function appears intact you can now begin to repair the wound.

Repair Materials
Many different materials may be used to repair turtle shells. In the past the most repairs were commonly done using a fiberglass patch and epoxy resin. Other patch materials include hoof repair compounds, colored polyester resins, and dental acrylic plastics. Most of these can be bought from a local hardware or hobby shop, or a distributor of dental products. The simplest repairs can be done with a small piece of wire and transparent dressing.

Repair Procedures
A proper repair procedure begins with preparation of the wound. The wound should be carefully lavaged using a dilute irrigating solution such as Nolvasan, povidone iodine solution, or 3% hydrogen peroxide. Once thoroughly cleaned and debrided the shell should be dried carefully. All of the repair techniques require a dry surface in order to adhere properly. All turtles with damaged shells should be placed on systemic antibiotics a minimum of one week or until the wound is sealed - whichever is longer. Open shell wounds should also be protected from flies by caging with protective screens.

Excavated holes
Wounds that result in the loss of bony shell or fragmentation of the shell in numerous small pieces that cannot be saved must be repaired using the patch method. This is done most simply by using dental acrylic as the patch. The surface of the shell is prepared by roughening the edges of the defect with a nail file or sandpaper. Make sure not to allow shell dust to invade the wound. The acrylic can then be prepared as directed on the package and formed into a flat patch and pressed over the defect. The patch should lie over the wound rather than fill it. Make sure the leading edges of the wound are not coated with the patch material as this will prevent the bone from bridging beneath the patch. New bone will bridge smaller defects within one to two years. Defects which are too large to bridge completely will be supported by the patch. If this repair technique is used in a younger animal those areas of the patch that overlie active growth line must be removed with a route or similar instrument to permit normal shell expansion. After a period of 48 hours in dry dock to allow the patch to thoroughly cure, the animal can then be returned to water.

Linear Cracks
Shell damage consisting of single or multiple linear cracks is best repaired by utilizing stainless wire (ask your vet) and a removable dressing (Transparent IV Dressing such as Tegaderm). The wound is cleaned and lavaged as the others and then thoroughly dried. A wooden tongue depressor is used to protect underlying tissues and is placed beneath the shell fragment to be repaired. A small hole is drilled into the shell a short distance (4-5mm) on either side of the crack. The smallest drill bit possible should be used to create these holes. A medium gauge (23-25) wire should be threaded through both holes with the free ends emerging from the dorsal surface (top). The ends are then tightened to bring the edges of the crack into position. The surface of the crack is again cleaned and dried and an adhesive dressing such as Tegaderm is applied to protect the wound until water tight. This usually takes a period of a few weeks. In the meantime the turtle should only be allowed a shallow dish of water that does not allow the defect to e submerged.

Bridge Fractures
Damage to the bridge area of a turtle shell can be a difficult problem to manage. A fracture in this area generally undergoes a great deal of movement with normal activity from the turtle. This movement makes patch repairs precarious at best. Occasionally bridges can be wired but the turtles anatomy usually makes this difficult as well. Many times these injuries must go unstabilized. In this case the underlying coelomic membrane will seal and the turtle will be left slightly more vulnerable.

Key Points

  • The most important things to keep in mind when repairing shell damage include:
  • The turtle must have full use of all its limbs.
  • The wound must be kept clean and sterile before and after repair.
  • The edges of the defect must remain uncoated to allow the shell to heal.
  • Growth lines must be allowed unrestricted growth.

The final condition of the repaired shell should not hamper the animals survival in the wild.

Related Articles

Treating Shell Rot

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