AVMA Euthanasia Guidelines – AAAP comments

SECTION: Physical Methods

Item: Cervical Dislocation

Current statements:

Cervical dislocation has been used for many years for euthanasia and, when performed by well-trained individuals, appears to be humane. However, there are few scientific studies available to confirm this observation. The method is used to euthanatize poultry other than turkeys, other small birds, mice, and immature rats and rabbits. Cervical dislocation does not cause immediate insensibility in turkeys (Erasmus, 2010). For mice and rats, the thumb and index finger are placed on either side of the neck at the base of the skull or, alternatively, a rod is pressed at the base of the skull. With the other hand, the base of the tail or the hind limbs are quickly pulled, causing separation of the cervical vertebrae from the skull. For immature rabbits, the head is held in one hand and the hind limbs in the other. The animal is stretched and the neck is hyperextended and dorsally twisted to separate the first cervical vertebra from the skull (Hughes, 1976; Clifford, 1984).

Data suggest that electrical activity in the brain persists for 13 seconds following cervical dislocation in rats (Vanderwolf, 1988), and unlike decapitation, rapid exsanguination does not contribute to loss of consciousness (Holson, 1992; Derr, 1991).

Advantages—(1) Cervical dislocation is a method that may induce rapid loss of consciousness (Iwarsson, 1993; Vanderwolf, 1988). (2) It does not chemically contaminate tissue. (3) It is rapidly accomplished.

Disadvantages—(1) Cervical dislocation may be aesthetically displeasing to personnel performing or observing the method. (2) Cervical dislocation requires mastering technical skills to ensure loss of consciousness is rapidly induced. (3) Its use for euthanasia is limited to poultry other than turkeys, other small birds, mice, and immature rats and rabbits.

Recommendations—Manual cervical dislocation is a humane method for euthanasia of poultry other than turkeys, other small birds, mice, rats weighing < 200 g, and rabbits weighing < 1 kg when performed by individuals with a demonstrated high degree of technical proficiency. In lieu of demonstrated technical competency, animals must be unconscious or anesthetized prior to cervical dislocation. The need for technical competency is greater for heavy rats and rabbits, in which the large muscle mass in the cervical region makes manual cervical dislocation physically more difficult (Keller, 1982). In research settings, this method should be used only when scientifically justified by the user and approved by the Institutional Animal Care and Use Committee.

Those responsible for the use of this method must ensure that personnel performing cervical dislocation have been properly trained and consistently apply it humanely and effectively.

Suggested changes from AAAP:

Cervical dislocation has been used for many years for euthanasia and, when performed by well-trained individuals, appears to be humane. However, there are few scientific studies available to confirm this observation. The method is used to euthanatize poultry other than turkeys, other small birds, mice, and immature rats and rabbits. Cervical dislocation does not cause immediate insensibility in turkeys (Erasmus, 2010). For poultry, the thumb and index finger are placed on either side of the neck of the bird at the base of the skull. Both legs (and feet) should be held with the other hand. The neck of the bird should then be manually stretched and then rotated with dorsal flexion in a swift and continuous motion to separate the cervical vertebrae from the skull.For mice and rats, the thumb and index finger are placed on either side of the neck at the base of the skull or, alternatively, a rod is pressed at the base of the skull. With the other hand, the base of the tail or the hind limbs are quickly pulled, causing separation of the cervical vertebrae from the skull. For immature rabbits, the head is held in one hand and the hind limbs in the other. The animal is stretched and the neck is hyperextended and dorsally twisted to separate the first cervical vertebra from the skull (Hughes, 1976; Clifford, 1984).

Data suggest that electrical activity in the brain persists for 13 seconds following cervical dislocation in rats (Vanderwolf, 1988), and unlike decapitation, rapid exsanguination does not contribute to loss of consciousness (Holson, 1992; Derr, 1991).

Advantages—(1) Cervical dislocation is a method that may induce rapid loss of consciousness (Iwarsson, 1993; Vanderwolf, 1988). (2) It does not chemically contaminate tissue. (3) It is rapidly accomplished.

Disadvantages—(1) Cervical dislocation may be aesthetically displeasing to personnel performing or observing the method. (2) Cervical dislocation requires mastering technical skills to ensure loss of consciousness is rapidly induced. (3) Its use for euthanasia is limited to poultry other than turkeys, other small birds, mice, and immature rats and rabbits.

Recommendations—Manual cervical dislocation is a humane method for euthanasia of poultry other than turkeys, other small birds, mice, rats weighing < 200 g, and rabbits weighing < 1 kg when performed by individuals with a demonstrated high degree of technical proficiency. In lieu of demonstrated technical competency, animals must be unconscious or anesthetized prior to cervical dislocation. The need for technical competency is greater for heavy rats and rabbits, in which the large muscle mass in the cervical region makes manual cervical dislocation physically more difficult (Keller, 1982). In research settings, this method should be used only when scientifically justified by the user and approved by the Institutional Animal Care and Use Committee.

Those responsible for the use of this method must ensure that personnel performing cervical dislocation have been properly trained and consistently apply it humanely and effectively.

Reason for change:

  1. Cervical dislocation is mentioned in the Conditionally Acceptable Physical Methods of the Poultry Section of the AVMA Guidelines for Animals Farmed for Food or Fiber. To maintain continuity in the AVMA guidelines, we believe that it should be clearly included for poultry species in the CervicalDislocation section. In the Conditionally Acceptable Physical Methods it mentions that cervical dislocation can be used for “poultry of an appropriate size and species and must be performed by experienced personnel who are regularly monitored for correct application of the technique.” It does not exclude the use for turkeys or any other poultry species in this section. By deleting the wording “other than turkeys” both sections will be parallel in the AVMA euthanasia guidance for this method.
  2. Cervical dislocation is commonly used by poultry-specialized veterinarians and personnel working with various poultry species. It is mentioned as an acceptable method of euthanasia for poultry in the EU Regulation (COUNCIL REGULATION (EC) No 1099/2009, page L303/19) on the Protection of Animals at the Time of Killing and in the 2009 NTF Guidelines (pg. 28).
  3. The Erasmus (2010) study included a very limited amount of birds (7 turkeys) for the experiment with cervical dislocation. The methodology utilized to assess consciousness in this study was not applied to all 7 turkeys receiving this treatment and the size and age of the turkeys used were not equivalent to other treatment methods. Furthermore, the actual assessments used by Erasmus et al are not parallel to those recommend by the AVMA for evaluation of insensibility following euthanasia. There are no additional scientific references available at this time to further verify the precise data findings for the comparison of cervical dislocation with other methods for adult poultry.
  4. For these reasons, we are suggesting the above modification for the AVMA guidelines.

Reference:

NTF Guidelines: