Fear, trembling, convulsions. They should never be used.
Dr. Michael R. Moyer, V.M.D., is the past Director of the Shelter Animal Medicine Program at the University of Pennsylvania School of Veterinary Medicine. He is also the past President of the American Animal Hospital Association, the past President of the Pennsylvania Veterinary Medical Association, and a recipient of the PVMA Veterinarian of the Year Award. These are his views on the use of gas chambers at animal shelters.
Most objections to carbon monoxide gas euthanasia begin with arguments around physiologic and conscious distress matters: whether animals suffer when being gassed. This is a legitimate concern, a concern that a reasonable person would find incompatible with a “humane euthanasia.” To put it simply, CO systems are cruel. Other objections focus on technical and safety issues (i.e., the dangers posed by CO systems to shelter workers). CO systems put staff at risk, are unreliable, require ongoing maintenance that is virtually non-existent in the shelter environment, and they desensitize workers tasked with protecting animals to animal suffering. There is a third dimension, however, which makes use of CO systems objectionable but which often goes unreported: even if all of these “technical” constraints could be overcome, the use of the gas chamber to kill animals would still be morally inhumane.
CO is Dangerous and Unreliable
Carbon monoxide is a highly toxic and flammable gas---indeed, the 2001 accidental death of a shelter worker in Tennessee tragically illustrated the extreme danger of carbon monoxide death systems. In order for it to rapidly and reliably cause death in dogs and cats, a high gas flow rate is required. Achieving that concentration in a chamber large enough to hold dogs and cats (often multiple dogs and cats) necessitates rapid gas flow through a regulator, producing a significant amount of noise that is frightening to the animals contained in the chamber. Flow rates below the noise threshold produce a slow, erratic onset of unconsciousness. The "recommended" target level is 6%, though there is a disconcerting and therefore inhumane uncertainty as to the time from introduction of the gas until the time unconsciousness is achieved.
Disturbingly, pediatric and geriatric, pregnant, physically sick or injured dogs and cats may suffer even more---their ability to survive in the face of low oxygen levels may be (counter-intuitively) enhanced, and their time to unconsciousness may be delayed beyond the expected range for healthy pets. Pregnancy and health status of pets entering shelters may not be reliably known, so it is certain that some of these animals would be subject to an even more inhumane death experience.
Use of these systems commonly involves placing multiple dogs or cats into the device simultaneously. The inability to precisely regulate gas flow to individual animals in the chamber, the extremely distressing effect of vocalization on those animals still conscious and agitated by the gas combine to make this a truly horrible experience for all of the unfortunate occupants of the machine. They do not, as may be commonly assumed, just "pass out" and "go to sleep." They thrash, they bark and whine and cry, they foul themselves; they convulse and twitch before they die.
Because of the considerable and obvious suffering inflicted, carbon monoxide systems desensitize animal shelter workers who use them to kill dogs and cats. Indeed, only a desensitized person could put animals into the device, close the door, push the button, step back and watch---knowing what is about to happen inside. Ironically, those hired to care for animals in need are forced to inflict this cruelty upon them as a part of their job duties.
Some argue that gas systems are appropriate for dangerous animals because it does not require "hands on" euthanasia by staff the way lethal injection would. But this argument ignores the necessity of not just moving those animals from their kennels to the euthanasia room, but then attempting to place those animals into a small, enclosed chamber. Any animal that can be managed into a chamber could be more safely and humanely tranquilized then given a lethal overdose of pentobarbital.
CO Systems Require High Maintenance
The carbon monoxide machine is complex and requires precisely fitted moving parts to secure the chamber door against leakage. The installation location must be open outdoors and monitored for stray CO. The machine must also monitor flow rate and concentration within the chamber (both complicated by its frequent use as a “batch killing” device). In short, these are not robust machines in an animal environment,
where debris and damage to equipment is unavoidable. It is common for animal welfare organizations to have poor preventative maintenance processes; this combination of high-maintenance requirement and an absent or poor maintenance process will result in even more inhumane performance of the machine and potentially dangerous conditions for the operators. Moreover, despite being capable of both intentional and
accidental death, there is no registration, inspection, or oversight of CO systems by any regulatory body.
The Moral Objection to CO Systems
There is, however, a different and perhaps more important point of stasis—rejection of the very premise upon which rationalization for gas chamber death is based: the false premise that mass death is necessary in animal sheltering. Even if one were to accept that it is necessary, the technical matters are sufficiently inhumane to thwart reasonable use of CO. But if one were to reject the premise that mass death is necessary, then even if every technical concern over use of CO systems were transformed away through innovation, the facts continue to compel resolute opposition to mechanized death for homeless dogs and cats under any circumstances.
Veterinarians and regulatory authorities often approach the issue of humane euthanasia, particularly in animal shelters, from a technical starting point, having already accepted fait accompli that mass killing is necessary. While there are real technical concerns with carbon monoxide chamber, mass killing of dogs and cats in the shelter environment is not necessary, good, or required. The premise that there are “too few homes” for the millions of pets entering shelters each year is belied by the millions of pets acquired by new and existing pet owners. The premise that pets entering shelters are “not adoptable” for health problems—problems that are seen, diagnosed, and treated by veterinarians in these very same communities—is not correct. They are treatable and adoptable in the vast majority of cases. The premise that there is some public good in taking free-roaming cats into shelters, terrorizing them in confinement for a stray hold, then killing them because they’re “unadoptable” is not merely Sisyphean, it is cruel and ineffectual at successfully managing free roaming cat populations or free roaming cat “nuisance” complaints.
Mass euthanasia is not required in animal control or animal sheltering. The enduring acceptance of killing as the major disposition option for dogs and cats in animal “sheltering” has allowed sub-standard and regressive organizations to not merely exist, but to thwart progressive organizations from achieving higher levels of life-saving. The term “shelter” in this context is bracketed because of the definition of sheltering (id est, “Protect or shield from something harmful, esp. bad weather, find refuge or take cover from bad weather or danger”). If one were to add “and then gas them in carbon monoxide until dead,” it would be seen as obscene farce. Yet that reality happens every day, under the camouflage of animal “sheltering.” Rationalization for use of gas chambers cites expediency or efficiency without re-examining the premise that massive
numbers of dogs and cats must be killed each year.
The continued acceptance of this approach, not to mention the facilitation of that process through mechanization, has caused the suffering and death of millions of dogs and cats each year for years. Making the delivery of death more facile by use of a machine (load, lock, push the button) is an approach that desensitizes animal welfare agencies to the core of the problem and utterly fails to improve the conditions leading to homelessness in dogs and cats. And this kill approach puts all of its intervention resources towards extermination of the symptom rather than developing effective and humane solutions to the fundamental problems that result in animals entering shelters.
The kill approach’s aim at symptom instead of solution perpetuates a cycle of killing, as the focus and resource allocation is aimed at extermination instead of prevention, foster, and adoption. These “unwanted,” “surplus,” “feral” animals, if presented under different circumstances to a typical veterinary office, would be treated if unwell, held for a potential owner, re-homed, or released. Veterinarians do this all the time. It takes a regressive and entrenched system and deliberate avoidance of known life-saving strategies to maintain and rationalize a process whereby imminently treatable and adoptable dogs and cats are killed instead of re-homed or, in the case of free-roaming cats, returned to their habitat. No community has created an animal welfare agency for the expressed purpose of mass killing of dogs and cats, and yet in many communities, animal shelters have been hijacked by management and governance boards that refuse to embrace life-saving changes.
CO Systems are Regressive and Cruel
There is no progressive sheltering agency of any scope or stature willing to philosophically embrace CO systems for euthanasia of any dog or cat. Humane sheltering is deliberately, inexorably, and philosophically moving away from mass killing as an acceptable method of dog and cat population control. That there are technical features of certain systems that distinguish it from other such systems should not be the
point of discussion. Efforts focusing on efficient killing strategies utterly fail to address the key social and resource causes of pet abandonment and failure to successfully rehome them.
Even if one were to reject the above premise, the use of the gas chamber cannot be justified. It is sickening to watch dogs and cats die in these machines. Their last act of human contact is to be sealed in a box stale with the odors of fear and death from the last “batch.” Frightened by the escaping gas sound, they move anxiously in their chamber—some frantic, others frozen by their fear and trembling. Technical papers describe
“vocalizations” to make it sound more clinical and academic, but even one unfamiliar with dogs and cats would know to identify it as fear and stress—barking, crying, whining, howling. As the hissing of gas flooding the box continues, animals become disorientated, fall, collapse; but instead of a quiet, limp faint towards stillness, there is thrashing of hyper-excitable muscles twitching in the poisoned air, convulsions, the
animals still “vocalizing,” animals in phases of these states of fear and anxiety and distress. Some of the animals urinate and some defecate in mortis extremis, adding disgust to the disgrace they’ve been fated to suffer.
It takes several minutes to finish the cycle and to purge the poison from the box, the dead bodies and the excreta must wait for the machine to be safe before it can be opened, the now silent and limp bodies to be removed. The machine is perfunctorily cleaned, and made ready for another “batch”. There is much killing to do, and there is no ceremony, no formality to the task of removing and stacking the cadavers. The logistics of handling bodies in death can be inelegant under the best of circumstances—here, in this process of group death, there is revulsion of every sense, and the wrongness of it screams and howls. No one who witnesses this can come away thinking that this is a “good death” for a dog or a cat.
In short, they should never be used.
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Selected References:
- Haldane J. The action of carbonic oxide in man. Journal of Physiology, 1895;18:430–462
- Raub JA, Mathieu-Nolf M, Hampson NB, et al. Carbon monoxide poisoning—a public health perspective. Toxicology 2000;145:1–14
- Hampson NB, Weaver LK. Carbon monoxide poisoning: a new incidence for an old disease. Undersea Hyperbaric Med 2007;34:163–168
- Lowe-Ponsford FL, Henry JA. Clinical aspects of carbon monoxide poisoning. Adverse Drug React Acute Poisoning Review 1989;8:217–240
- Bloom JD. Some considerations in establishing divers’ breathing gas purity standards for carbon monoxide. Aerospace Medicine 1972;43:633–636
- Norman CA, Halton DM. Is carbon monoxide a workplace teratogen? A review and
evaluation of the literature. Annals of Occupational Hygiene 1990;34:335–347
- Wojtczak-Jaroszowa J, Kbow S. Carbon monoxide, carbon disulfide, lead and cadmium---four examples of occupational toxic agents linked to cardiovascular disease. Medical Hypotheses, 1989;30:141-150
- Fechter LD. Neurotoxicity of prenatal carbon monoxide exposure. Respiratory
Reproductive Health Effects Institute 1987;12:3–22.
- Ramsey TL, Eilmann HJ. Carbon monoxide acute and chronic poisoning and experimental
studies. Journal of Laboratory Clinical Medicine. 1932;17:415–427.
- Enggaard Hansen N, Creutzberg A., Simonsen HB. Euthanasia of mink (Mustelavison) by means of carbon dioxide (CO2), carbon monoxide (CO) and nitrogen (N2). British Veterinary Journal. 1991;147:10-146.
- Vinte FJ. The humane killing of mink. London: Universities Federation for Animal Welfare, 1957.
- Chalifoux A, Dallaire A. Physiologic and behavioral evaluation of CO euthanasia of adult
dogs. American Journal of Veterinary Research. 1983;44:2412–2417.
- Dallaire A, Chalifoux A. Premedication of dogs with acepromazine or pentazocine before euthanasia with carbon monoxide. Canadian Journal of Comparative Medicine 1985;49:171-178.
- Weary DM, Makowska IJ. Rat aversion to carbon monoxide.
Applied Animal Behavioral Science. 2009;121:148–151.
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