What Are Animal Sentinels?
Domestic or wildlife animals may be "sentinels" if they give early warning of
infection or chemical health threats in the environment.
Some well-known areas of study considering animals as sentinels include:
Canaries in Coal Mines
Well into the 20th century, coal miners in England and the US brought
canaries into coal mines as an "early warning signal" for carbon monoxide and
other poisonous gases. The birds, being more sensitive, would become sick before
the miners, who would then have a chance to escape or put on protective
Emerging Infectious Diseases
The discovery of West
Nile Virus in the western hemisphere was heralded by an outbreak of disease
in wild birds. Other emerging diseases have demonstrated linkages
between animal health events and human risk, including Monkeypox,
Some speculate that animals could provide early warning of a
terrorist attack using biological or chemical agents. For example,
released from a Soviet weapons facility, livestock died at a
greater distance from the plant compared to human cases.
Endocrine Disrupting Chemicals?
In recent years, reports of reproductive problems in animal populations,
including developmental abnormalities and behavioral disturbances, have prompted
concerns that chemical exposures could be affecting both animals and humans.
Yet the evidence linking the animal disease events to human health is limited
(see this Canary Database
record for details about one of these studies).
Pets and household exposures
provide early warning of lead
poisoning hazards in a home, and
certain cancers in dogs and cats have been linked to household pesticides. Pets may also provide early warning of risks from infectious diseases
including Lyme Disease.