Secondary poisoning, or relay toxicity, is the poisoning that results when one

organism In biology, an organism () is any life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy (biology), taxonomy into groups such as Multicellular o ...

comes into contact with or ingests another organism that has

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

in its system. It typically occurs when a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

eats an animal, such as a

mouse A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

, or

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

, that has previously been poisoned by a commercial pesticide. If the level of

toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

in the prey animal is sufficiently high, it will harm the predator. Mammals susceptible to secondary poisoning include

humans Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

, pets such as

cats The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

and

dogs The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relativ ...

, as well as wild

birds Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

Pesticides

Various pesticides such as

rodenticides Rodenticides are chemicals made and sold for the purpose of killing rodents. While commonly referred to as "rat poison", rodenticides are also used to kill mice, squirrels, woodchucks, chipmunks, porcupines, nutria, beavers, and voles. Despite ...

may cause secondary poisoning.Rodenticides: Topic Fact Sheet

National Pesticide Information Center The National Pesticide Information Center (NPIC) is a collaboration between Oregon State University and the United States Environmental Protection Agency to provide objective, science-based information about pesticides, the recognition and manage ...

Some pesticides require multiple feedings spanning several days; this increases the time a target organism continues to move after ingestion, raising the risk of secondary poisoning of a predator. Most of slow-acting poisons for pests have cumulative effects and so can cause secondary poisoning and environment pollution. {, class="wikitable sortable" , - ! Pesticide ! Type ! Classification ! Target ! Oral Toxicity ! Feedings ! Secondary Risk to Mammals ! Secondary Risk to Birds , - ,

Warfarin Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent ...

, Anticoagulant , Hydroxycoumarin , Rodenticide , Moderate , Multiple , Low , Minimal , - , Bromadiolone , Anticoagulant , Hydroxycoumarin , Rodenticide , High , Single , Moderate , Moderate , - , Difethialone , Anticoagulant , Hydroxycoumarin , Rodenticide , High , Single , Moderate , Highest , - ,

Brodifacoum Brodifacoum is a highly lethal 4-hydroxycoumarin vitamin K antagonist anticoagulant poison. In recent years, it has become one of the world's most widely used pesticides. It is typically used as a rodenticide, but is also used to control larger pe ...

, Anticoagulant , Hydroxycoumarin , Rodenticide , Highest , Single , Highest , Highest , - , Chlorophacinone , Anticoagulant , Indandione , Rodenticide , High , Multiple , Highest , Minimal , - , Diphacinone , Anticoagulant , Indandione , Rodenticide , High , Multiple , Highest , Moderate , - , Bromethalin , CNS , other , Rodenticide , High , Single , Low , Low , - , Fluoroacetate , Metabolism , other , Rodenticide , Highest , Single , High , Highest , - , Zinc phosphide , other , other , Rodenticide , High , Single , Minimal , Low

References

Toxicology