Pet Pathway Toolkit: Working together to save pets from becoming invasive species

What is the Pet Pathway Toolkit?

The Pet Pathway Toolkit assists governments, the pet industry, and their partners in establishing programs and policies that prevent the release or escape of pets into the natural environment, where they can become invasive species.

Why is the Pet Pathway Toolkit important?

Pets that have escaped or been released can become invasive species—predators or competitors with native wildlife, that can spread disease and/or parasites. In addition, aquaria dumping and water gardening can become a source of invasive plants.

Invasive species (harmful non-native organisms) are a major threat to native wildlife and habitats. The pet trade has been identified as one source of potentially invasive species. In order to minimize this invasion risk, the Parties to the Convention on Biological Diversity (CBD) adopted the decision in 2008 to study best management practices that industries, governments, and others are taking to prevent the release, escape, and establishment of former pets and aquaria species.

As a result, the Pet Industry Joint Advisory Council and the Global Invasive Species Programme (GISP) worked collaboratively to create the Pet Pathway Toolkit with generous financial support from government agencies and the private sector.

Invasion Risks

Invasive alien species (harmful non-native organisms) are considered one of the major threats to native wildlife and habitats worldwide. The escape and release of former pets has been identified as a source (pathway) for the introduction of invasive animals into natural environments. Not only can these former pets become invasive, but so can other organisms associated pets and pet care.

Possible sources of invasive alien species introduction through the pet trade pathway include:


  • Release of unwanted pets or live pet food (e.g., feeder fish, crickets);
  • Outdoor disposal of unwanted plant material associated with aquariums, terrariums, or water gardens that house pets;
  • Outdoor disposal of pet food containing viable seeds or rootable plant material;


  • Escape of pets or live pet food that are poorly contained;
  • Introduction of pathogens and parasites that “hitchhike” on pets or organisms used for live pet food that are released or escape; and
  • Introduction of plant material, pathogens, or parasites when pet housing (e.g., aquariums/terrariums, bird cages), toys, feeding dishes, and other supplies are cleaned outdoors.

Many (perhaps most) pets and associated organisms that escape or are released into the natural environment are unable to survive due to inappropriate climatic conditions, predation, or the hazards of human development (e.g., road traffic). However, under ideal conditions, not only do these organisms survive, they thrive and become invasive alien species - causing significant harm to the environment, human and animal health, and/or the economy.

The greatest risks for the introduction of animals through the pet trade pathway are likely to be associated with:

  • Release by/escape from consumers (pet owners). Commercial businesses have an economic interest in protecting their “inventory;”
  • Non-regulated direct sales – such as sales through the internet and newspapers, hobbyist shows, flea markets, etc. This is a rapidly growing segment of the pet industry. People who purchase pets in this manner may be making “spontaneous purchases” that are not well thought through and they may be more likely to receive animals that are in poor condition (i.e. more likely to have pathogens or parasites);
  • Pets that are free or inexpensive. Because there is relatively little financial investment in these animals, the owners may be more included to release them when they no longer wish to care for them;
  • Species which grow large, reproduce easily and in large numbers in captivity, have specialized dietary or other husbandry requirements, and have aggressive temperaments. These animals require a relatively greater investment of care and money. Owners who are not prepared to meet the animals’ needs may choose to release them; and
  • Species ecologically suited to the geographic region in which they are maintained as pets. When these animals enter the natural environment they have the potential to survive the weather conditions. If they can reproduce, they might establish a viable population and spread

Escaped/released pets can predate upon and compete with native wildlife, threatening entire ecosystems. They can also spread pathogens and parasites to people, livestock, pets, and wildlife. In some cases, former pets can become agricultural pests.

When plants (including seeds) associated with pet care enter the natural environment, they can establish and spread to such an extent that they outcompete native plants and cause wide-scale disruptions to ecological systems. Some invasive aquatic plants have become so abundant that they hinder boating and recreational fishing.

Examples of invasive alien species that were likely introduced, intentionally or unintentionally, into natural environments through the pet trade pathway include:

  • Red-eared turtles (Trachemys scripta elegans) (also human food pathways)
  • American bullfrogs (Lithobates catesbeianus; formerly Rana catesbeiana) in water gardens (also human food pathways and bait)
  • Monk/Quaker parakeets (Myiopsitta monachus)
  • Lionfish (Pterois volitans) (also possible introduction by divers and public aquarium)
  • Feral domestic cat (Felis domesticus/Felis catus)

For more information on the pet trade pathway in general, we invite you to read the attached article entitled, HabitatittudeTM: Getting a Backbone about the Pet Release Pathway.

For more information on the pet trade pathway and disease, we invite you to read the attached article entitled, All Creatures Great and Minute: A Public Policy Primer for Companion Animal Zoonoses.

Key Terms

Alien Species Species, subspecies or lower taxon, introduced outside its natural past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce (CBD Guiding Principles). Sometimes also called: non-native species, non-indigenous species, or exotic species.
Invasive Alien Species An alien species whose introduction and/or spread threaten biological diversity (CBD Guiding Principles). Some definitions also include threats to human health, animal health, and the economy.
Sometimes also called: invasive species, invasive non-native species, injurious wildlife, noxious weed, plant pest, or unwanted organism
Introduction The movement by human agency, indirect or direct, of an alien species outside of its natural range (past or present). This movement can be either within a country or between countries or areas beyond national jurisdiction (CBD Guiding Principles).
Risk Assessment The evaluation of the likelihood of entry, establishment or spread of a pest or disease within the territory of an importing Member according to the sanitary or phytosanitary measures which might be applied, and of the associated potential biological and economic consequences’ (WTO-SPS Agreement).
Environmental biosecurity Protection of the environment and social amenity from the negative effects associated with invasive species; including weeds, pests and diseases. It occurs across the entire biosecurity continuum: pre-border preparedness, border protection and post-border management and control (Australian biosecurity policy).

ANSTF U.S. Aquatic Nuisance Species Task Force
CBD Convention on Biological Diversity
CITES Convention on International Trade in Endangered Species of Wild Fauna and Flora
EPPO European and Mediterranean Plant Protection Organization
EU European Union
GISP Global Invasive Species Programme
IPPC International Plant Protection Convention
IUCN International Union for the Conservation of Nature
NISC US National Invasive Species Council
OIE World Organization fro Animal Health
SBSTTA CBD Subsidary Body on Scientific, Technical, and Technological Advice
SPS WTO Agreement on the Application of Sanitary and Phytosanitary Measures
UNEP United Nations Environment Programme
WTO World Trade Organization

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