Euthanasia & Carcass Disposal

Module 10    Euthanasia & Carcass Disposal

Euthanasia means good death (“eu” = good; “thanasia” = death), and refers to techniques that are used to kill an animal as painlessly as possible. To be considered euthanasia, death must occur instantaneously or while the animal is unconscious.

 Learning Objectives

  1. Compare and contrast the differences between capture methods and euthanasia techniques.
  2. Explain the reasons for using proper euthanasia techniques.
  3. Identify signs that confirm death of an animal.
  4. Explain when a method meets guidelines of the American Veterinary Medical Association (AVMA).
  5. List options for appropriate disposal of carcasses.

Introduction

While some sharpshooters are able to shoot animals so precisely that animals die without suffering, euthanasia usually occurs in a controlled setting, such as at an animal clinic or shelter.

Because euthanasia is difficult to accomplish in the field, sometimes humane killing techniques must be used instead. Humane killing involves the rapid death of an animal, but it may still experience brief pain or distress. Humane killing does not meet the criteria for euthanasia because the animal experiences pain.

Examples of humane killing include snap traps for mice and rats. While their primary function is to capture the animal, the animal often dies rapidly enough to be considered humane killing. While the distinctions between euthanasia and humane killing may seem trivial, they must be kept in mind to have a realistic discussion about the use of lethal control for wildlife.

Certainly, euthanasia techniques should be used whenever practical as the animal will suffer the least. In situations where euthanasia is impractical, use humane killing techniques. Regardless of the method used to kill an animal, reduce stress to the animal as much as possible.

The emotional involvement people have with wildlife dictates that all killing of wildlife, whether by euthanasia, humane-killing, or capture device, be done out of public view. In addition, make every reasonable effort to reduce stress to animals before and during efforts to kill them. Failure to follow this advice may result in a great deal of scrutiny and unwanted attention.

Disposition of Injured Wildlife

Wild animals that are captured, injured, and unfit to be released in accordance with state, county, or city regulations normally should be euthanized or humanely killed. Check your state and local laws BEFORE you begin any control program.

Euthanasia Techniques

Carbon dioxide

Many people in the wildlife control industry consider euthanasia by carbon dioxide-induced narcosis to be the most user-friendly of the methods recommended by the AVMA. The method requires a chamber in which CO2 replaces the available oxygen. With this method, the animal can be euthanized without injection, handling, or transfer.

Carbon dioxide (CO2) is readily available at welding supply centers, is relatively safe for humans to use, and will suppress the ability of an animal to experience pain prior to death. For commercial operators, a euthanasia chamber (Figure 1) is essential. They can be purchased from various supply companies or constructed on your own.

For more information on how to build and use a CO2 chamber, consult the Internet Center for Wildlife Damage Management (http://icwdm.com).

10_1_Cage_Trap_In_Carbon_Dioxide_Euthanasia_Chamber
Figure 1. A cage trap enclosed in a carbon-dioxide euthanasia chamber constructed with Plexiglas®. Photo by Stephen M. Vantassel.

Shooting

Personnel should be trained in the safe use of firearms and the anatomy of the species involved. We do not recommend that non-professionals be involved in euthanizing animals by shooting. However, shooting is a common and useful control method for trained professionals. State and local laws often restrict firearm discharge in non-rural areas.
For more information on shooting as a control method, consult the Internet Center for Wildlife Damage Management (http://icwdm.com).

Humane Killing Techniques

Shooting a free-ranging animal is a common form of humane killing. Snap traps capture animals while humanely killing them.

Other kill traps (e.g., tunnel traps and body-gripping traps) also are suitable devices to accomplish humane killing. Because these devices require additional training, we suggest that readers consult their state wildlife agency or contact experienced trappers or wildlife control professionals first.

Confirmation of Death

Confirmation of death can be difficult in field settings. We recommend that you consider all the possible signs when determining whether the animal truly is deceased.

  1. Respiration has stopped – check to see if the chest has stopped expanding and contracting for at least 3 minutes. You may have to look carefully, as some animals have very shallow breathing.
  2. Corneal reflex has ceased – the animal should no longer blink (even when touching the eye), the eyes should be fixed, and the pupils (the black portion of the eye) dilated.
  3. Muscle tone is limp – dead animals will not be able to stand and should appear limp and flaccid.
  4. Heart has stopped beating – a stethoscope and training are needed to determine if an animal is dead.

Disposal of Carcasses

Disposal of carcasses must be done safely, in a manner respectful of public sensitivities, and in accordance with state and local guidelines. Proper disposal methods include:

  • aboveground,
  • belowground, single-use burial area,
  • belowground, repeated-use burial area,
  • incineration, and
  • disposal in a licensed landfill.

Always wear thick leather gloves to reduce the risk of being scratched or exposed to animal fluids when handling carcasses. Welder’s gloves are durable and provide protection to the hands and wrists. For additional protection, wear latex or vinyl gloves inside the leather gloves (Figure 2). Ticks and fleas present a health risk as they leave the dead carcass in search of a new host.

10_2_Various_Gloves
Figure 2. Top left and moving clockwise: Latex gloves, rubberized cloth gloves, and welder’s gloves. Photo by Stephen M. Vantassel

Aboveground

Aboveground disposal is easy because no digging is involved. It is gaining in popularity as an environmentally-responsible way of recycling wildlife in the ecosystem. Aboveground disposal increases the likelihood of attracting scavengers that feed on carcasses.

Aboveground disposal requires landowner permission and is not recommended for carcasses of sick or poisoned animals. Choose isolated locations to reduce encounters with pets and people, and do not overuse a location. Sites should be more than 150 feet from ponds, streams, and wells. Runoff from the site should not flow toward water sources.

Belowground individual grave

Bury animals in individual graves.

  1. Consult with companies that locate underground utilities, such as Dig Safe® or Diggers Hotline prior to digging.
  2. Choose burial sites that are at least 300 feet from surface water to reduce the risk of contamination.
  3. Bury carcasses at least 4 feet belowground (Figure 3). If this is not practical, ensure that the carcasses are covered with sufficient materials, such as rocks, to reduce the possibility of access by scavengers.
10_3_Woodchuck_In_Individual_Grave
Figure 3. Woodchuck placed in an individual grave, prior to burial. Photo by Stephen M. Vantassel.

Incineration

The incinerator must be approved by state and local authorities to burn animal carcasses. Incineration can cost more than $0.50 per pound, making it relatively expensive. Contact your local veterinarian for details on incineration sites. A burn barrel is not an incinerator. It cannot sustain the required high temperatures for a long enough period of time.

Landfill

Carcasses taken to a landfill must be securely enclosed in a plastic bag or other suitable airtight container to prevent noxious odors. They may be disposed of at a Type-II, licensed, solid-waste disposal facility (standard landfill), or at an out-of-state facility, in accordance with that state’s solid waste disposal regulations.

Additional Resources

AVMA Guidelines on Euthanasia (2012) at http://www.avma.org/issues/animal_welfare/ euthanasia.pdf
http://wildlifecontroltraining.com
http://icwdm.com/
http://wildlifecontrol.info

Questions for Reflection

  1. What does euthanasia mean?
  1. What is humane killing and how is it different from euthanasia?
  1. Provide three signs that you would use to determine if an animal is dead.
  1. List the methods of carcass disposal and explain the requirements for their use.
  1. A landowner grants permission for surface disposal of carcasses. What questions must be answered before disposing of any carcasses.