Animal sentinels
Encyclopedia
There is increasing recognition that wild, domestic, and companion animals may act as "sentinels" for environmental health
hazards by providing early warning of human health hazards in the environment. Animals can act as sentinels because they may be more susceptible or have greater exposure to a particular hazard compared to humans living nearby.
in the coal mine
". Well into the 20th century, coal miners in the United Kingdom
and the United States
brought canaries into coal mines as an early-warning signal for toxic gases including methane
and carbon monoxide
. The birds, being more sensitive, would become sick before the miners, who would then have a chance to escape or put on protective respirators.
in the western hemisphere was heralded by an outbreak of disease in crows and other wild birds. Other emerging diseases have demonstrated linkages between animal health events and human risk, including Monkeypox
, SARS, and Avian Influenza.
hazards in a home, and certain cancers in dogs and cats have been linked to household exposures to pesticides, cigarette
smoke, and other carcinogens.
(infectious diseases of animal origin), animals could also be at risk from a terrorism attack and may be first to show signs of illness due to increased exposure or susceptibility. For example, when anthrax
was inadvertently released from a Soviet weapons facility in Sverdlovsk
, livestock died at a greater distance from the plant compared to human cases.
in a "One Health" approach that recognizes disease events in non-human species may indicate human health risk. The "One Health" approach involves greater information sharing between human health and veterinary clinicians and public health professionals and cooperative efforts to identify and prevent diseases that act across species barriers in a way that is mutually beneficial.
Environmental health
Environmental health is the branch of public health that is concerned with all aspects of the natural and built environment that may affect human health...
hazards by providing early warning of human health hazards in the environment. Animals can act as sentinels because they may be more susceptible or have greater exposure to a particular hazard compared to humans living nearby.
Detection of toxic gases
The classic example of animals serving as sentinels is the "canaryDomestic Canary
The Domestic Canary, often simply known as the canary, is a domesticated form of the wild Canary, a small songbird in the finch family originating from the Macaronesian Islands ....
in the coal mine
Coal mining
The goal of coal mining is to obtain coal from the ground. Coal is valued for its energy content, and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United States,...
". Well into the 20th century, coal miners in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
brought canaries into coal mines as an early-warning signal for toxic gases including methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
and carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
. The birds, being more sensitive, would become sick before the miners, who would then have a chance to escape or put on protective respirators.
Infectious diseases
The discovery of West Nile VirusWest Nile virus
West Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...
in the western hemisphere was heralded by an outbreak of disease in crows and other wild birds. Other emerging diseases have demonstrated linkages between animal health events and human risk, including Monkeypox
Monkeypox
Monkeypox also known as cockpox is an exotic infectious disease caused by the monkeypox virus. The disease was first identified in laboratory monkeys, hence its name, but in its natural state it seems to infect rodents more often than primates...
, SARS, and Avian Influenza.
Household toxin hazards
Dogs may provide early warning of lead poisoningLead poisoning
Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems...
hazards in a home, and certain cancers in dogs and cats have been linked to household exposures to pesticides, cigarette
Cigarette
A cigarette is a small roll of finely cut tobacco leaves wrapped in a cylinder of thin paper for smoking. The cigarette is ignited at one end and allowed to smoulder; its smoke is inhaled from the other end, which is held in or to the mouth and in some cases a cigarette holder may be used as well...
smoke, and other carcinogens.
Cancer detection
A study has shown that dogs, with often only relatively short training, can detect lung and breast cancer trace elements in the breath of people with these cancers, and clearly distinguish them from the breath of healthy subjects.Terrorist events
Some speculate that animals could provide early warning of a terrorist attack using biological or chemical agents. Since most potential bioterrorism threats are zoonosesZoonosis
A zoonosis or zoonoseis any infectious disease that can be transmitted from non-human animals to humans or from humans to non-human animals . In a study of 1415 pathogens known to affect humans, 61% were zoonotic...
(infectious diseases of animal origin), animals could also be at risk from a terrorism attack and may be first to show signs of illness due to increased exposure or susceptibility. For example, when anthrax
Anthrax
Anthrax is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals...
was inadvertently released from a Soviet weapons facility in Sverdlovsk
Yekaterinburg
Yekaterinburg is a major city in the central part of Russia, the administrative center of Sverdlovsk Oblast. Situated on the eastern side of the Ural mountain range, it is the main industrial and cultural center of the Urals Federal District with a population of 1,350,136 , making it Russia's...
, livestock died at a greater distance from the plant compared to human cases.
"One Health"
Recently, there has been a call for linkage of human and veterinary medicineVeterinary medicine
Veterinary Medicine is the branch of science that deals with the prevention, diagnosis and treatment of disease, disorder and injury in non-human animals...
in a "One Health" approach that recognizes disease events in non-human species may indicate human health risk. The "One Health" approach involves greater information sharing between human health and veterinary clinicians and public health professionals and cooperative efforts to identify and prevent diseases that act across species barriers in a way that is mutually beneficial.