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Euthanasia Of Live Prey

Introduction:

The topic of feeding live prey to pet and other animals has enjoyed a lot of attention during the last few years. Although there are various different opinions regarding the feeding of live prey and the feeding of prey to other animals, the purpose of this section is not to discuss the controversy regarding weather its right or wrong, but merely to aid in the humane euthanasia of prey animals. Euthanasia is defined as an easy or painless death. We are faced with the fact that various pet animals around the world consume prey animals as main source of food, but there are huge amounts of pressure us as owners of these animals to rather resort to the feeding of dead prey. The actual problem is that there are not a lot of information on how to we can actually kill these prey animals humanely. This section will mainly discuss various ways of- and aspects around the euthanasia of food animals such as rats, mice, guinea pigs, lagomorphs and chickens.

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Reasons For Euthanasia Include:

Safer to feed (see the Live Vs. Dead Prey section)
Seen as more humane & ethical to feed dead prey
The feeding of live prey is prohibited by law in some countries
It allows for effective preservation of prey items
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Bonking, Stunning & Related Methods:

Bonking is done by filliping (shooting with the finger) the animal on the head, where the degree of force will either stun or kill it. This technique is effective on rodents up to the size of a small rat. Another effective method that is especially being used on rats and large mice is the so-called "side of the table method" where the animal is held by its tail and "swinged" in such a way that the head collides with the side of a hard surface. Much force should be used so that the chances of survival is minimized. Some people prefer to throw the entire animal against the floor or wall for a similar effect.

These techniques were experimentally proven to be a cruel and inhumane method to stun and kill rodents and are generally not acceptable

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Anesthetics & Euthanasia Agents:

Anesthetic agent (agents or drugs used to abolish the sensation of pain and to reduce fear and anxiety) overdose and registered euthanasia agents are considered to be a good humane and ethical way to euthanase an animal. These agents should be administered directly into the vasculature or the heart of the animal or, more commonly in smaller animals, into the abdominal cavity. The problems however with these two techniques are that these agents are scheduled drugs and it can only be administered by a registered veterinarian and that the administration thereof is relatively expensive. Another drawback is that one run the risk of administrating unmetabolised drugs to the animal consuming the prey.

These methods are unpractical & potentially dangerous to the animal consuming the prey

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Cervical Dislocation:

Some reports conditionally finds cervical dislocation to be an acceptable method to euthanase mice and small rats (less than 200 g / 7 oz). Research data suggest that electrical activity in the brain persists for thirteen seconds following cervical dislocation during which spasmic contractions occur. For this reason the jury is still out on the technique.

For this technique the animal is picked up by the base of the tail and is allowed to grip on a secure, non-movable surface like the bars of a cage, the tail is gently pulled backwards against the pull of the animal while the neck immediately behind the head is firmly pinched and slightly twisted with the other hand. This will dislocate and crush the cervical / neck veterbra of the animal. Alternatively a rod or ruler can be pushed down on the neck while pulling the tail. This method takes some practice to master and it is strongly recommended to learn the procedure under supervision to ensure humane killing.

To my opinion this is the best method if one does not have a lot of animals to kill or have access to carbon dioxide for asphyxiation

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Asphyxiation:

Asphyxiation techniques are enjoying a lot of active research lately, especially in the field of laboratory animals. According to recent studies the best (most humane) way to euthanase rats and mice (and probably most other prey animals) is to asphyxiate or suffocate them in a controlled environment with carbon dioxide (CO2) gas.

CO2 sources include:

Dry ice which available from ice cream shops, ice retailers & artificial insemination institutes, semen retailers & evaluation labs
Bottled CO2 available from suppliers like AFROX (South Africa) & other medical gas suppliers

Asphyxiation should only be applied in a small controlled environment. A small, sealable "asphyxiation chamber" can be constructed or any commercial small sized see-through container with a tight fit lid capable of trapping gas can be used. Bottled CO2 can then be blown through one of two small (about 2 cm / 1 ") holes drilled in the center of two opposite sides or dry ice can be placed inside the container within an isolating carton box to prevent direct contact. Dry ice should be handled with caution and one should use appropriate gloves or a towel when handling it.

Different exposure rates are suggested by different scientists. Some argue that the asphyxiation chamber should already contain a high concentration CO2 (higher is better) before the animal is inserted while other state that the concentration should be gradually increased (flow rate of about 2ℓ / min) when the animal is already inside. Both parties have valid reasons and proof for their point of view.

The following points should be applied when euthanasing more than one animal at the same time:

Prevent overcrowding to reduce possible injuries
Never euthanase different sizes of the same species or different species at the same time in the same container
Remove all CO2 before immediate re-use of the chamber

Asphyxiation techniques are the most researched, most humane and at this stage probably the most accepted way of euthanasing prey animals, especially when it comes to killing large numbers of animals at once

"If you think I should add more information to this section or think that something is incorrect, contact me and let me know. I would love to hear your ideas or methods you might use that is different than ours."

Last updated 16 June 2007 by Renier Delport

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