How best to euthanize a horse?

(Beth Clifton collage)

You recently wrote these sentences that are at odds with best and standard practices in the horse industry: “But horses are rarely killed by pentobarbital, since the required dose would be about 100 times the average dose for a dog and several hundred times the average dose for a cat. Rather, when horses are euthanized due to incurable illness or injury, whether in a stable, a field, a busy street, or alongside a trail or racetrack, the usual instrument of dispatch is a captive bolt gun, the same instrument used in a slaughterhouse.”

Horses in need of humane euthanasia are dispatched with an injection. In an emergency, they may be shot. In 50 years of owning horses and working in the racing and sport-horse industries, I have never had a horse euthanized by captive bolt and none of my veterinarians carry such an instrument. A portable captive bolt device may have been used before injectable euthanizing drugs were developed. The use of the captive bolt has been eclipsed, is archaic, and poses some risk to the administrators — they are powered by a shot.

May I ask where you obtained the information on current use of captive bolt?

––Liz O’Connell, Red Hook, New York

<liz@thoroughbredconfidential.com>

<www.thoroughbredconfidential.com>

(Beth Clifton collage)

Response:

Captive bolt guns are recommended as the preferred method for euthanizing horses on pages 35 and 63-64 of the American Veterinary Medical Association Guidelines for the Euthanasia of Animals: 2013 edition.

Use of the captive bolt with horses has long been in disfavor in Britain, but elsewhere, whether the captive bolt or pentobarbital injection is preferable is still a topic of debate. Kimberly S. Brown, a leading reporter on horse-related topics for more than 30 years, in the April 2004 edition of The Horse presented an interesting discussion of the pros and cons of captive bolt vs. pentobarbital: <www.thehorse.com/articles/14580/captive-bolt-controversy>.

The issues Brown raised are still those of most concern.

We requested additional perspective from Sharon Cregier, Ph.D., North American co-ordinator for the Equine Behaviour Forum, a contributing editor to Equine Behaviour Journal, a frequent contributor to the International Journal for the Study of Animal Problems and Equus, and an advisor to the Animal Transport Association, Farm Animal Welfare Council of Great Britain, the Commonwealth Agricultural Bureau, and the Royal SPCA.

(Beth Clifton collage)

Sharon Cregier’s response:

Both of my horses were euthanized by needle. However, I have reservations about the practice. A fellow horse expert has advised me that a bullet is preferable to pentobarbital injection because the bullet is instant, whereas the needle forces the horse to suffer the pain of something similar to a sudden heart stoppage. Horses administered the needle do sometimes react with a forward surge, but this is said to be reflexive only, and not an effort to escape pain.

The AVMA’s criteria is that the euthanasia method must be instantaneous without causing pain or distress, be safe for personnel and bystanders, and take into consideration the emotional effect on observers and administrator. The AVMA’s complete guidelines are on their website.

There are four methods of horse euthanasia approved by the AVMA, the USDA, the Humane Slaughter Association, and the U.S. Public Health Service. These are chemical, bullet, captive bolt, and fatal bleeding of an unconscious animal.

Depending on the method, the horse can be brain dead, as in a captive bolt administration, but the heart and lungs may continue to function for minutes or hours after the horse is insentient.

The barbiturate route anesthetizes the brain and stops the contraction of the heart.

There is a lot more detail on this in Rebecca Gimenez, Tomas Gimenez and Kimbery A. May’s book Technical Large Animal Emergency Rescue (2008).

Rebecca Gimenez Husted.
(Facebook photo)

Rebecca Gimenez’s response:

My preference for horse euthanasia is a gunshot or a penetrating captive bolt. When done properly, with the weapon in the correct position, this is efficient, instantaneous, and effective. We teach both to animal control officers, other law enforcement personnel, and horse and cattle owners.

The bolt must be followed by a secondary method, thus the neck slit in slaughter after shooting, because the bolt sometimes does not destroy the respiratory center. But inducing pneumothorax or slitting the great arteries and veins is very efficient.

Beth & Merritt Clifton.
(Geoff Geiger photo)

Chemical euthanasia has some serious downsides to the environment, and is done mostly to allow the horse owner to think that the death is prettier and nicer. Many vets have told me that it is their worst nightmare to do chemical euthanasia on difficult horses. Other vets have admitted in private that it is a practice builder. It is easier to charge for something mysterious than for a 40-cent bullet.