If you wish to listen to an audio recording of this module, please click here. (Duration: 4:25)

Introduction

Veterinarians know about the importance of humane euthanasia – it is crucial for reducing the suffering of animals with poor prognoses. Many of the turtles that arrive at TRT, and some of those who will present to your clinic, have severe traumatic injuries that are not survivable (i.e., crushed skull) or that make survival in the wild impossible (i.e., bilateral blindness or loss of more than one limb). In these instances, you will need to know how to provide humane euthanasia in a turtle.

Special Considerations

As discussed in other modules in this course, turtles have certain quirks that must be kept in mind during euthanasia procedures.

• Venous access can be difficult, especially if the turtle has lost a lot of blood or typical routes of IV access are damaged
• The heartbeat of a turtle can continue for hours after administration of pentobarbital, making confirmation of death difficult. Secondary measures of euthanasia are necessary to ensure that the turtle is brain dead.

As with all other species, turtles must be sedated before administration of pentobarbital and they must be unconscious for most secondary euthanasia measures. At TRT, we usually sedate with a combination of dexmedetomidine (0.05-0.1 mg/kg) and ketamine (5-10 mg/kg) 10-20 minutes prior to euthanasia – these drugs can be given IM or IV.

Pharmaceutical Methods

Sodium pentobarbital is the most common drug used for euthanasia at TRT and is administered IV at 1 mL/kg or higher. The easiest access points are the occipital sinus, the subcarapacial sinus in smaller turtles, or the caudal tail vein in larger turtles. If these sites are inaccessible due to trauma, the brachial or femoral vein can be used, or the drug can be injected intracoelomically if no other options are available. Alternatively, you can deliver pentobarbital via an intracardiac stick, though this can be difficult in turtles because of their shell. A doppler probe can be used to determine the position of the heart to guide intracardiac injection.

Potassium chloride (2 mEq/kg) can also be used for intracardiac injections following sedation.

Physical Methods

Physical methods are used as an adjunctive form of euthanasia following administration of drugs. Once the pupils are fixed and a corneal reflex is absent, it is safe to perform these methods to confirm death. In TRT, we most commonly utilize pithing, in which a large-gauge (>18G) needle is inserted through the foramen magnum and moved in a swirling motion to destroy the brain tissue. Other physical methods include captive bolt and decapitation. Please see Nevarez 2019 for illustrations on how to locate the brain for the captive bolt method.

Confirmation of Death

Confirming death in reptile patients is a controversial subject. The AVMA recommends that a physical method be used in all cases to confirm death. Once the brain tissue is destroyed, you can be confident that the patient has been successfully euthanized. The heartbeat alone cannot be used to confirm death.

Relevant Videos

Pithing

Additional Resources

• AVMA Guidelines on Euthanasia (2020)
• Nevarez JG. Euthanasia. Chapter 47 in, Divers SJ and Stahl SJ (Eds.), Mader’s Reptile and Amphibian Medicine and Surgery, 3rd Ed., Amsterdam:Elsevier, 2019.