Euthanasia

Statement of Purpose

These links and documents contain information about best practices for euthanasia.

Contributors

Content generated during The American Society of Ichthyologists and Herpetologists (ASIH) Annual Joint Meeting - 2016, during an iDigBio sponsored workshop by the following individuals participating in the "Field to Database" Group of the aforementioned workshop: Breda Zimkus, Cesar Aguilar, Ben Frable, Meredith Mahoney, Zachary Randall, and David Wernecke.

Institutional Animal Care and Use Committee (IACUC)

Most research institutions require that field practices, including euthanasia methods, be approved by IACUC. Be aware that some euthanasia methods used may not be allowed by IACUC at your particular institution. Ensure that you are able to transport any controlled substances needed for approved euthanasia method. Note: IACUC preferred methods (e.g. pentobarbital) may not be easy to use in the field or may not be allowed in some countries.

General Recommendations

• Remember to conduct any live-color photography prior to euthanizing to preserve color.

General Methods

check Simmons for standard v. less common methods, examples are from Auburn Tetrapod person, should we note this

• MS-222 (Tricaine methanesulfonate); use a freshly mixed solution every few days

-Example amphibian methods: Water bath of MS-222 solution. 5-10g/L for overdose (possibly use higher number to be sure and to speed up the process). Anesthetic levels would be less (Surgical anesthesia in adult frogs: 1 to 2 g/liter Tadpoles: 0.2 to 0.5 g/liter). 3 g/L seems to be the tipping point. (Penn IACUC guidelines) The solution should buffered to neutral (7.0-7.5 pH) with sodium bicarbonate before use.

-Example reptile method: It is a two-step process with an injection of a 1% solution followed by a 50% solution.

-Fish must be held 21 days before release if anaesthitized with MS-222

• Ice-bath
• Cooling then freezing (Shine et al. 2015)
• Clove oil (Note: This cannot be used if fish may be consumed by people)
• Pithing

-Flex the neck, identify the foramen magnum, insert a rigid metal rod cranially, and pivot/rotate the rod within the cranium to destroy the proximal spinal cord and brain.

Herpetology Specific Methods

• Sodium pentobarbital (e.g. Beuthanasia®, Euthasol®, Fatal-Plus®, Somlethal®).
• Example reptile method: twice the dosage for euthanasia in mammals (for dogs the dosage is 1 mL/10 pounds). This comes out to be about 4.4 mL/Kg. Since herps are usually small the amounts are not that great, so over dose to be sure.
• Commercial Euthanasia Solution (Sodium pentobarbital 390 mg + sodium phenytoin 50 mg/ml) 0.22 ml/kg IV, ICL (~86 mg/kg pentobarbital)
• Beuthanasia can affect animals feeding on carcasses that have been injected, so any animals not ending up in the collection must be incinerated.
• Sodium pentobarbital is alkaline (11.0 pH) and can be cut with water to reduce pain at injection. Possibly also the case with Beauthanasia-D.
• Benzocaine (Orajel®) for amphibians or thin-skinned reptiles; apply to head or venter
• Chloretone/Chlorobutanol
• Make saturated solution, dilute or use. Use as a bath (25%) for amphibians, can inject reptiles (not sure about dilution).
• Use fresh solution periodically, solution loses efficacy with use.
• Ether
• Cotton soaked in ethyl acetate (i.e., nail polish remover) in killing jar
• MS-222 (50mg/L??) immersion (amphibians)
• MS-222 injection (reptiles)
• Benzocaine (amphibians)
• Ethyl acetate
• Directly into formalin (5-10%) (e.g., larval); see subsampling below
• Directly into ethanol (10%)
• Freezing

Fishes

• MS-222-immersion
• Directly into formalin (5-10%) (e.g., larval fishes); see subsampling below
• Directly into ethanol (70-95%)
• Freezing (ice and water bath)