Animal euthanasia (
euthanasia
Euthanasia (from el, εὐθανασία 'good death': εὖ, ''eu'' 'well, good' + θάνατος, ''thanatos'' 'death') is the practice of intentionally ending life to eliminate pain and suffering.
Different countries have different eut ...
from el, εὐθανασία; "good death") is the act of killing an animal or allowing it to die by withholding extreme medical measures. Reasons for euthanasia include incurable (and especially painful) conditions or diseases, lack of resources to continue supporting the animal, or laboratory test procedures. Euthanasia methods are designed to cause minimal pain and distress. Euthanasia is distinct from
animal slaughter
Animal slaughter is the killing of animals, usually referring to killing domestic livestock. It is estimated that each year 80 billion land animals are slaughtered for food. Most animals are slaughtered for food; however, they may also be slau ...
and
pest control
Pest control is the regulation or management of a species defined as a pest; any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range ...
although in some cases the procedure is the same.
In
domesticated
Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A ...
animals, this process is commonly referred to by
euphemism
A euphemism () is an innocuous word or expression used in place of one that is deemed offensive or suggests something unpleasant. Some euphemisms are intended to amuse, while others use bland, inoffensive terms for concepts that the user wishes ...
s such as "put down" or "put to sleep".
Methods
The methods of euthanasia can be divided into pharmacological and physical methods. Acceptable pharmacological methods include injected drugs and gases that first depress the central nervous system and then cardiovascular activity. Acceptable physical methods must first cause rapid loss of consciousness by disrupting the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
. The most common methods are discussed here, but there are other acceptable methods used in different situations.
Intravenous anesthetic
Upon administration of intravenous anesthetic, unconsciousness,
respiratory
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies grea ...
then
cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
follow rapidly, usually within 30 seconds.
Some veterinarians perform a two-stage process: an initial injection that simply renders the pet unconscious and a second shot that causes death. This allows the owner the chance to say goodbye to a live pet without their emotions stressing the animal. It also greatly mitigates any tendency toward spasm and other involuntary movement which tends to increase the emotional upset that the pet's owner experiences.
For large animals, the volumes of
barbiturates
Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as ...
required are considered by some to be impractical, although this is standard practice in the United States. For horses and cattle, other drugs may be available. Some specially formulated combination products are available, such as Somulose (
secobarbital
Secobarbital (as the sodium salt, originally marketed by Eli Lilly and Company for the treatment of insomnia, and subsequently by other companies as described below, under the brand name Seconal) is a short-acting barbiturate derivative drug that ...
/
cinchocaine
Cinchocaine (INN/ BAN) or dibucaine (USAN) is an amide local anesthetic. Among the most potent and toxic of the long-acting local anesthetics, current use of cinchocaine is generally restricted to spinal and topical anesthesia. It is sold under th ...
) and Tributame (
embutramide
Embutramide (International Nonproprietary Name, INN, United States Adopted Name, USAN, British Approved Name, BAN) (brand name Embutane) is a potent opioid analgesic and sedative drug that is structurally related to methadone. It was developed by ...
/
chloroquine
Chloroquine is a medication primarily used to prevent and treat malaria in areas where malaria remains sensitive to its effects. Certain types of malaria, resistant strains, and complicated cases typically require different or additional medi ...
/
lidocaine
Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lidoca ...
), which cause deep unconsciousness and cardiac arrest independently with a lower volume of injection, thus making the process faster, safer, and more effective.
Occasionally, a horse injected with these mixtures may display apparent
seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...
activity before death. This may be due to premature cardiac arrest. However, if normal precautions (e.g.,
sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, ...
with
detomidine
Detomidine is an imidazole derivative and α2-adrenergic agonist, used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride. It is a prescription medication available to veterinari ...
) are taken, this is rarely a problem. Anecdotal reports that long-term use of
phenylbutazone
Phenylbutazone, often referred to as "bute", is a nonsteroidal anti-inflammatory drug (NSAID) for the short-term treatment of pain and fever in animals.
In the United States and United Kingdom, it is no longer approved for human use (except in th ...
increases the risk of this reaction are unverified.
After the animal has died, it is not uncommon for the body to have posthumous body jerks or a sudden bladder outburst.
Inhalants
Gas anesthetics such as
isoflurane
Isoflurane, sold under the brand name Forane among others, is a general anesthetic. It can be used to start or maintain anesthesia; however, other medications are often used to start anesthesia rather than isoflurane, due to airway irritation w ...
and
sevoflurane
Sevoflurane, sold under the brand name Sevorane, among others, is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used as an inhalational anaesthetic for induction and maintenance of general anesthesia. After desflura ...
can be
used for euthanasia of very small animals. The animals are placed in
sealed chambers where high levels of anesthetic gas are introduced. Death may also be caused using
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
once unconsciousness has been achieved by inhaled anaesthetic.
Carbon dioxide is often used on its own for euthanasia of wild animals. There are mixed opinions on whether it causes distress when used on its own, with human experiments lending support to the evidence that it can cause distress and equivocal results in non-humans.
In 2013, the American Veterinary Medical Association (AVMA) issued new guidelines for carbon dioxide induction, stating that a flow rate of 10% to 30% volume/min is optimal for the humane euthanization of small rodents.
[2013 AVMA Guidelines for the Euthanasia of Animals](_blank)
/ref>
Carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
is often used, but some states in the US have banned its use in animal shelters: although carbon monoxide poisoning is not particularly painful, the conditions in the gas chamber are often not humane. Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
has been shown to be effective, although some young animals are more resistant to the effects, and it currently is not widely used.
Cervical dislocation
Cervical dislocation
Cervical dislocation is a common method of animal euthanasia. It refers to a technique used in physical euthanasia of small animals by applying pressure to the neck and dislocating the spinal column from the skull or brain. , or displacement (breaking or fracturing) of the neck, is an older and less common method of killing small animals such as mice. Performed properly it is intended to cause as painless a death as possible and has no cost or equipment involved. The handler must know the proper method of executing the movement which will cause the cervical displacement and without proper training and method education there is a risk of not causing death and can cause severe pain and suffering. It is unknown how long an animal remains conscious, or the level of suffering it goes through after a correct snapping of the neck, which is why it has become less common and often substituted with inhalants.
Intracardiac or intraperitoneal injection
When intravenous injection
Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutri ...
is not possible, euthanasia drugs such as pentobarbital
Pentobarbital (previously known as pentobarbitone in Britain and Australia) is a short-acting barbiturate typically used as a sedative, a preanesthetic, and to control convulsions in emergencies. It can also be used for short-term treatment of ...
can be injected directly into a heart chamber or body cavity.
While intraperitoneal injection
Intraperitoneal injection or IP injection is the injection of a substance into the peritoneum (body cavity). It is more often applied to animals than to humans. In general, it is preferred when large amounts of blood replacement fluids are needed ...
is fully acceptable (although it may take up to 15 minutes to take effect in dogs and cats[), an intracardiac (IC) injection may only be performed on an unconscious or deeply sedated animal. Performing IC injections on a fully conscious animal in places with humane laws for animal handling is often a criminal offense.
]
Shooting
This can be a means of euthanasia for large animals—such as horses, cattle, and deer—if performed properly.
This may be performed by means of:
; Firearms
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions).
The first firearms originated in 10th-century China, when bamboo tubes c ...
: Traditionally used in the field for euthanizing horses, deer or other large game animals. The animal is shot in the forehead with the bullet directed down the spine through the medulla oblongata
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...
, resulting in instant death. The risks are minimal if carried out by skilled personnel in a suitable location.
; Captive bolt gun
A captive bolt (also variously known as a cattle gun, stunbolt gun, bolt gun, or stunner) is a device used for stunning animals prior to Slaughter (livestock), slaughter.
The goal of captive bolt stunning is to inflict a forceful strike on the ...
: Commonly used by the meat packing industry
The meat-packing industry (also spelled meatpacking industry or meat packing industry) handles the slaughtering, processing, packaging, and distribution of meat from animals such as cattle, pigs, sheep and other livestock. Poultry is generally no ...
to slaughter cattle and other livestock. The bolt is fired through the forehead causing massive disruption of the cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...
. In cattle, this stuns the animal, though if left for a prolonged period it will die from cerebral oedema
Cerebral edema is excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compressio ...
. Death should therefore be rapidly brought about by pithing
Pithing is a technique used to immobilize or kill an animal by inserting a needle or metal rod into its brain.
It is regarded as a humane means of immobilizing small animals being observed in experiments, and while once common in commercial slau ...
or exsanguination
Exsanguination is death caused by loss of blood. Depending upon the health of the individual, people usually die from losing half to two-thirds of their blood; a loss of roughly one-third of the blood volume is considered very serious. Even a sing ...
. Horses are killed outright by the captive bolt, making pithing and exsanguination unnecessary.
Reasons
The reasons for euthanasia of pets and other animals include:
* Terminal illness
Terminal illness or end-stage disease is a disease that cannot be cured or adequately treated and is expected to result in the death of the patient. This term is more commonly used for progressive diseases such as cancer, dementia or advanced he ...
, e.g. cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
or rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, vi ...
* Illness or accident that is not terminal but would cause suffering for the animal to live with, or when the owner cannot afford, or when the owner has a moral
A moral (from Latin ''morālis'') is a message that is conveyed or a lesson to be learned from a story or event. The moral may be left to the hearer, reader, or viewer to determine for themselves, or may be explicitly encapsulated in a maxim. A ...
objection to the treatment
* A hunter's coup de grâce
A coup de grâce (; 'blow of mercy') is a death blow to end the suffering of a severely wounded person or animal. It may be a mercy killing of mortally wounded civilians or soldiers, friends or enemies, with or without the sufferer's consent.
...
* Behavioral problems (usually ones that cannot be corrected) e.g. aggression
Aggression is overt or covert, often harmful, social interaction with the intention of inflicting damage or other harm upon another individual; although it can be channeled into creative and practical outlets for some. It may occur either reacti ...
– Canines that have usually caused grievous bodily harm
Grievous bodily harm (often abbreviated to GBH) is a term used in English criminal law to describe the severest forms of battery. It refers to two offences that are created by sections 18 and 20 of the Offences against the Person Act 1861. The ...
(severe injuries or death) to either humans or other animals through mauling are usually seized and euthanized ('destroyed' in British legal terms)
* Old age and deterioration leading to loss of major bodily functions, resulting in severe impairment of the quality of life
* Lack of home or caretaker or resources for feeding
* Research and testing – In the course of scientific research or testing, animals may be euthanized in order to be dissected
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause ...
, to prevent suffering after testing, to prevent the spread of disease, or other reasons[
Small animal euthanasia is typically performed in a veterinary clinic or hospital or in an ]animal shelter
An animal shelter or pound is a place where stray, lost, abandoned or surrendered animals – mostly dogs and cats – are housed. The word "pound" has its origins in the animal pounds of agricultural communities, where stray livestock would ...
and is usually carried out by a veterinarian
A veterinarian (vet), also known as a veterinary surgeon or veterinary physician, is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, vet ...
or a veterinary technician
Paraveterinary worker is the professional of veterinary science that performs procedures autonomously or semi autonomously, as part of a veterinary assistance system. The job role varies throughout the world, and common titles include veterinary n ...
working under the veterinarian's supervision. Often animal shelter workers are trained to perform euthanasia as well. Some veterinarians will perform euthanasia at the pet owner's home—this is virtually mandatory in the case of large animal euthanasia. In the case of large animals which have sustained injuries, this will also occur at the site of the accident, for example, on a racecourse.
Some animal rights
Animal rights is the philosophy according to which many or all sentient animals have moral worth that is independent of their utility for humans, and that their most basic interests—such as avoiding suffering—should be afforded the sa ...
organizations support animal euthanasia in certain circumstances and practice euthanasia at shelters that they operate.
Legal status
In the U.S., for companion animals euthanized in animal shelter
An animal shelter or pound is a place where stray, lost, abandoned or surrendered animals – mostly dogs and cats – are housed. The word "pound" has its origins in the animal pounds of agricultural communities, where stray livestock would ...
s, most states prescribe intravenous injection as the required method. These laws date to 1990, when Georgia's Humane Euthanasia Act became the first state law to mandate this method. Before that, gas chamber
A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. Poisonous agents used include hydrogen cyanide and carbon monoxide.
Histor ...
s and other means were commonly employed. The Georgia law was resisted by the Georgia Commissioner of Agriculture, Tommy Irvin
Thomas Telford Irvin (July 14, 1929 – September 14, 2017) was an American politician who served as Georgia's Commissioner of Agriculture from 1969 until January 2011. Irvin holds a record as the longest-serving Commissioner of Agriculture in ...
, who was charged with enforcing the act. In March 2007, he was sued by former State Representative Chesley V. Morton
Chesley V. Morton Jr. (born August 21, 1951) is an American stockbroker, securities arbitrator, and former member of the Georgia House of Representatives.
Biography
Early years and education
Chesley V. Morton Jr. was born in Miami, Florida on Au ...
, who wrote the law, and subsequently ordered by the court to enforce all provisions of the Act.
Some states allow the use of carbon monoxide chambers for euthanasia.
Remains
Many pet owners choose to have their pets cremated or buried after the pet is euthanized, and there are pet funeral home
A funeral home, funeral parlor or mortuary, is a business that provides burial and funeral services for the dead and their families. These services may include a prepared wake and funeral, and the provision of a chapel for the funeral.
Services
...
s that specialize in animal burial or cremation. Otherwise, the animal facility will often freeze the body and subsequently send it to the local landfill.
In some instances, animals euthanized at shelters or animal control agencies have been sent to meat rendering facilities to be processed for use in cosmetics
Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect ...
, fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
, gelatin
Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also ...
, poultry feed
Poultry feed is food for farm poultry, including chickens, ducks, geese and other domestic birds.
Before the twentieth century, poultry were mostly kept on general farms, and foraged for much of their feed, eating insects, grain spilled by cattl ...
, pharmaceuticals
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...
and pet food
Pet food is animal feed intended for consumption by pets. Typically sold in pet stores and supermarkets, it is usually specific to the type of animal, such as dog food or cat food. Most meat used for animals is a byproduct of the human food indu ...
. It was proposed that the presence of pentobarbital
Pentobarbital (previously known as pentobarbitone in Britain and Australia) is a short-acting barbiturate typically used as a sedative, a preanesthetic, and to control convulsions in emergencies. It can also be used for short-term treatment of ...
in dog food may have caused dogs to become less responsive to the drug when being euthanized. However, a 2002 FDA study found no dog or cat DNA in the foods they tested, so it was theorized that the drug found in dog food came from euthanized cattle and horses. Furthermore, the level of the drug found in pet food was safe.
See also
* Animal chaplains
A chaplain is, traditionally, a cleric (such as a minister, priest, pastor, rabbi, purohit, or imam), or a lay representative of a religious tradition, attached to a secular institution (such as a hospital, prison, military unit, intelligen ...
* Animal loss
The loss of a pet or an animal to which one has become emotionally bonded oftentimes results in grief which can be comparable with the death of a human loved one, or even greater, depending on the individual. The death can be felt more intensely ...
* Animal slaughter
Animal slaughter is the killing of animals, usually referring to killing domestic livestock. It is estimated that each year 80 billion land animals are slaughtered for food. Most animals are slaughtered for food; however, they may also be slau ...
* Animal welfare
Animal welfare is the well-being of non-human animals. Formal standards of animal welfare vary between contexts, but are debated mostly by animal welfare groups, legislators, and academics. Animal welfare science uses measures such as longevity ...
* British Pet Massacre
The British pet massacre was an event in 1939 in the United Kingdom where over 750,000 pets were killed in preparation for food shortages during World War II.
* Chick culling
Chick culling or unwanted chick killing is the process of separating and killing unwanted (male and unhealthy female) chicks for which the intensive animal farming industry has no use. It occurs in all industrialised egg production, whether fr ...
* Dysthanasia (animal)
* Insect euthanasia
* Overpopulation in companion animals In some countries there is an overpopulation of pets such as cats, dogs, and exotic animals. In the United States, six to eight million animals are brought to shelters each year, of which an estimated three to four million are subsequently euthani ...
* Pet
A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence, ...
* Rainbow Bridge (pets)
The Rainbow Bridge is the theme of several works of poetry written in the 1980s and 1990s that speak of an other-worldly place where pets go upon death, eventually to be reunited with their owners. One is a prose poem whose original creator is u ...
References
External links
AVMA Guidelines on Euthanasia
''Euthanasia of Animals Used for Scientific Purposes''
at The University of Adelaide
The University of Adelaide (informally Adelaide University) is a public research university located in Adelaide, South Australia. Established in 1874, it is the third-oldest university in Australia. The university's main campus is located on N ...
World Internet News chronicles what happens to abandoned dogs.
Reasons to euthanize your pet at home
National Agricultural Library, United States Department of Agriculture
No Kill Advocacy Center – "no kill" shelter advocacy organization
Deep Article on Dog Euthanasia - Everything you need to know
Recommendations for euthanasia of experimental animals: Part1
Recommendations for euthanasia of experimental animals: Part2
Chesley V. Morton v. Georgia Department of Agriculture and Tommy Irvin in his Official Capacity as Commissioner
{{Death
Animal euthanasia