Animal Categorization Scheme

What to know

To support analyses of outbreaks reported through the Animal Contact Outbreak Surveillance System (ACOSS), CDC categorizes animals into three increasingly specific levels: biologic class, major group, and subgroup.

Purpose

This animal categorization scheme helps public health, regulatory, and animal health professionals use ACOSS data to

  • describe which animal categories are most often linked to enteric (intestinal) disease outbreaks
  • identify animals that spread the pathogens (bacteria, viruses, or parasites) causing the most outbreak-related illnesses
  • improve understanding of outbreak characteristics linked to specific animal categories
  • inform recommendations and policies
  • assess prevention strategies and measure progress in disease prevention

Categorizing animals is part of a larger initiative to improve the collection, quality, and usefulness of data from animal contact outbreaks. This work could be expanded to include animals that transmit non-enteric pathogens.

Levels

The levels are based on each animal's biological characteristics, common settings of exposure, or interactions with humans. For example, a wild dog would be classified as:

  • Level 1 (Biologic Class): Mammal
  • Level 2 (Major Group): Canine
  • Level 3 (Subgroup): Wild canine

All Animals

Small mammals

  • Rodents
  • Chiroptera (e.g., bats)
  • Other small mammals (e.g., rabbits)

Felines

  • House/domestic cats
  • Non-domestic cats (e.g., mountain lions)

Canines

  • Domestic dogs
  • Wild canines (e.g., wolves)

Ruminants

  • Bovine (e.g., cattle)
  • Ovine (e.g., sheep)
  • Caprine (e.g., goats)
  • Cervidae (e.g., deer)
  • Other ruminants

Non-ruminant hooved mammals

  • Swine (e.g., pigs)
  • Equine (e.g., horses)
  • Camelid (e.g., camels)
  • Other non-ruminant hooved mammals

Non-human primates

  • Monkeys
  • Apes
  • Other non-human primates

Marine mammals

  • Aquatic mammals
  • Semi-aquatic mammals
  • Other aquatic mammals

Other mammals

Poultry, gamebirds, & waterfowl

  • Poultry* (e.g., chickens)
  • Gamebirds
  • Non-domesticated waterfowl

*Domesticated birds kept by humans for their eggs, meat, or feathers.

Seabirds, shorebirds, and wading birds

  • Seabirds
  • Shorebirds
  • Wading birds

Birds of prey

  • Falconiformes (e.g., hawks)
  • Strigiformes (e.g., owls)

Flightless birds

  • Ratites (e.g., ostriches)
  • Other flightless birds

Parrots (psittacine birds)

Passerines

  • Finches
  • Warblers
  • Other passerines

Other birds

Testudines (turtles)

  • Turtles, smaller than 4 inches
  • Turtles, larger than 4 inches
  • Tortoises

Squamates

  • Snakes
  • Lizards

Crocodilians

  • Crocodiles
  • Alligators

Other reptiles

Anura (tailless amphibians)

  • Frogs
  • Toads

Cuadata (tailed amphibians)

  • Salamanders
  • Newts

Other amphibians

Freshwater fish

Saltwater fish

Other fish

Collaborators

This animal categorization scheme reflects a collaborative effort among CDC's Enteric Diseases Epidemiology Branch, One Health Office, and Outbreak Response and Prevention Branch; the U.S. Department of Agriculture's Animal and Plant Health Inspection Service; and the Food and Drug Administration's Center for Food Safety and Applied Nutrition. The structure and goals of the scheme align with those of the Interagency Food Safety Analytics Collaboration (IFSAC) Food Categorization Scheme published in 2017, which is used to characterize foods linked to outbreaks.

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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)