Evaluation for SARS-CoV-2 Testing in Animals
Revisions were made on August 12, 2020 to reflect the following:
- Updates were made to the footnotes for Table 1 to clarify the definition of an animal’s exposure to SARS-CoV-2.
Note: The scientific name of the new strain of coronavirus is SARS-CoV-2. In people, the disease caused by the virus is called Coronavirus Disease 2019, also known as COVID-19. Because we are addressing the virus itself in the context of animal health, we refer to it as SARS-CoV-2.
This guidance was collaboratively developed by the Centers for Disease Control and Prevention, US Department of Agriculture, and other federal agencies using a One Health approach. It may be adapted by state and local health departments to respond to rapidly changing local circumstances.
- Routine testing of animals for SARS-CoV-2 is not recommended.
- The decision to test an animal, including companion animals, livestock, and wild or zoo animals, should be agreed upon using a One Health approach with the appropriate local, state, and/or federal public health and animal health officials.
- This document provides recommendations to guide priorities for animal SARS-CoV-2 testing given limited resources.
- Veterinarians are strongly encouraged to rule out other, more common causes of illness in animals before considering SARS-CoV-2 testing.
Who this guidance is for: This guidance was developed for use by state public health veterinarians and state animal health officials.
Purpose: This guidance is intended to guide decisions and help prioritize situations that may warrant SARS-CoV-2 testing in mammalian animal species given limited resources.
This guidance is intended to guide decisions and help prioritize situations that may warrant SARS-CoV-2 testing in mammalian animal species given limited resources. The decision to test an animal, including companion animals, livestock, and wild or zoo animals, should be made collaboratively using a One Health approach between local, state, and/or federal public health and animal health officials. Animal testing for SARS-CoV-2 is available if public health and animal health officials agree the animal’s case merits testing. Table 1 (below) is not intended to be prescriptive, but is rather intended to help guide priorities given limited resources. Routine testing of animals for COVID-19 is not recommended. Confirmatory testing through USDA’s National Veterinary Services Laboratories (NVSL) is not currently available for non-mammalian animals including reptiles, amphibians, birds, or fish.
Currently, there is no evidence that animals can transmit this virus to people. In some rare situations, people have spread this virus to certain types of animals. Veterinarians are strongly encouraged to rule out other, more common causes of illness in animals before considering SARS-CoV-2 testing. To discuss testing an animal for SARS-CoV-2 in certain circumstances, veterinarians should contact their state public health veterinarian pdf icon[137 KB, 7 pages]external icon1 or designated state official responsible for animal-related issues in public health; and/or their state animal health officialexternal icon2.
Limited information is currently available to characterize SARS-CoV-2 infection in animals; please visit CDC’s COVID-19 and Animals page for the most up-to-date information. Clinical criteria for considering testing for SARS-CoV-2 in animals is based on what is currently known about SARS-CoV-2 and COVID-19 and is subject to change as additional information becomes available.
Human patients with COVID-19 have symptoms that appear 2-14 days after exposure and include fever, cough, and shortness of breath. The clinical spectrum of SARS-CoV-2 infection in animals is currently unknown, but animals may present with a combination of respiratory symptoms or gastrointestinal illness based on presentation in a small number of animals and what is known about other coronaviruses, including SARS-CoV-13. Veterinarians should use their best judgment to determine if an animal has been exposed to people with suspected or confirmed COVID-19 and if the animal has clinical signs compatible with SARS-CoV-2 infection3. Table 1 describes epidemiological risk factors and clinical features that can help guide decisions regarding animal testing.
If public health and animal health2 officials determine that testing an animal for SARS-CoV-2 is appropriate, coordination between One Health partners will be needed. Please refer to USDA’s FAQsexternal icon for sample collection, transport, storage, and result reporting. If samples are sent to state animal health, university, or private laboratories for initial testing, duplicate samples should be collected because any positive samples must be confirmed through additional testing by NVSL. USDA is responsible for reporting any animal that tests positive for SARS-CoV-2 in the United States to the World Organisation for Animal Health (OIE)external icon.
Table 1: Criteria to Guide Evaluation and Laboratory Testing for SARS-CoV-2 in Animals
| Criteria | Epidemiological Risk | Clinical Features | |
|---|---|---|---|
| A | Animal with history of exposure4 to a person or animal suspected or confirmed to be infected with SARS-CoV-2. | AND | Animal has clinical signs suspicious of SARS-CoV-2 infection.3 |
| B | Animal with exposure to a known high-risk environment (i.e., where human cases or animal cases have occurred), such as a residence, facility, or vessel (e.g. nursing home, prison, cruise ship). | ||
| C | Threatened, endangered or otherwise imperiled/rare animal5 in a rehabilitation or zoological facility with possible exposure to SARS-CoV-2 through an infected person or animal. | AND | Animal is asymptomatic; OR Animal has clinical signs suspicious of SARS-CoV-2 infection.3 |
| D | Animals in a mass care or group setting (e.g., farm, animal feeding operation, animal shelter, boarding facility, zoo, or other animal holding) including companion animals, livestock, and other species, where their exposure history to people with COVID-19 is unknown. | AND | A cluster of animals show clinical signs suspicious of SARS-CoV-2 infection.3 |
Footnotes
NOTE: Veterinarians are strongly encouraged to rule out other, more common causes of illness in animals before considering SARS-CoV-2 testing.
1 Some jurisdictions do not have state public health veterinarians, or geographic, resource, or time limitations may prevent a state public health veterinarian from managing a situation involving an animal.
2 State animal health officials should contact state wildlife officials for decisions concerning non-captive wildlife.
3 Although the clinical spectrum of illness for this virus remains largely undefined in animals, clinical signs more likely to be compatible with SARS-CoV-2 infection in mammalian animals may include a combination of the following:
- Fever
- Coughing
- Difficulty breathing or shortness of breath
- Lethargy
- Sneezing
- Nasal discharge
- Ocular discharge
- Vomiting
- Diarrhea
4 Exposure is defined as:
- Being within approximately 6 feet (2 meters) of a person with suspected or confirmed COVID-19 starting from 2 days before the person’s illness onset (or, for asymptomatic human patients, 2 days before positive specimen collection) until the time the person is isolated.
- Having direct contact with infectious secretions from a person with suspected or confirmed COVID-19 starting from 2 days before the person’s illness onset (or, for asymptomatic human patients, 2 days before positive specimen collection) until the time the person is isolated. Direct contact could include an animal being coughed, sneezed, or spit on by an infected person or sharing food or consuming something that was recently contaminated with an infected person’s mucous or saliva.
5 The International Union for the Conservation of Nature (IUCN) governs an assessment of the status of species ranging from “critically endangered” to “least concern”: https://www.iucnredlist.org/external icon