Skip to main content

U.S. flag An official website of the United States government

Animal and Plant Health Inspection Service
U.S. Department of Agriculture
USDA FAQ's and resources about coronavirus (COVID-19).  LEARN MORE

Confirmation of COVID-19 in Hyenas at a Colorado Zoo


Washington, D.C., November 5, 2021 -- The United States Department of Agriculture’s (USDA) National Veterinary Services Laboratories (NVSL) today announced confirmation of SARS-CoV-2 (the virus that causes COVID-19) in two spotted hyenas at a zoo in Colorado.  These are the first hyenas confirmed with the SARS-CoV-2 virus worldwide. 

Samples from a variety of species at the zoo, including the hyenas, were collected and tested after lions at the facility showed signs of illness.  In addition to the two hyenas, eleven lions and two tigers at the zoo also tested positive for the virus.

Samples from the hyenas tested presumptive positive at the Colorado State University Veterinary Diagnostic Laboratory and the cases were confirmed at NVSL. NVSL serves as an international reference laboratory and provides expertise and guidance on diagnostic techniques, as well as confirmatory testing for foreign and emerging animal diseases. Such testing is required for certain animal diseases in the United States in order to comply with national and international reporting procedures. The World Organisation for Animal Health (OIE) considers SARS-CoV-2 an emerging disease, and therefore USDA must report confirmed U.S. animal infections to the OIE.

SARS-CoV-2 infections have been reported in multiple animal species worldwide, mostly in animals that had close contact with a person with COVID-19. At this time, routine testing of animals is not recommended. The decision to test an animal, including companion animals, livestock or production animals, zoo animals, or wild animals (both captive and free-ranging), should be agreed upon using a One Health approach with the appropriate local and/or state officials as well as USDA and CDC. USDA will announce cases of confirmed SARS-CoV-2 in animals each time the virus is found in a new species. Confirmed cases in animals are posted at

While additional animals may test positive as infections continue in people, it is important to note that performing this animal testing does not reduce the availability of tests for humans.

We are still learning about SARS-CoV-2 in animals. Based on the information available, the risk of animals spreading the virus to people is considered to be low.

People with COVID-19 can spread the virus to animals during close contact. It is important for people with suspected or confirmed COVID-19 to avoid contact with animals, including pets, to protect them from possible infection. 

For more information about COVID-19 and animals and recommendations for pet owners and people who work around animals, visit CDC’s COVID-19 and Animals website at

 For more information about how and when to test animals, visit and


USDA touches the lives of all Americans each day in so many positive ways. In the Biden-Harris Administration, USDA is transforming America’s food system with a greater focus on more resilient local and regional food production, fairer markets for all producers, ensuring access to safe, healthy and nutritious food in all communities, building new markets and streams of income for farmers and producers using climate smart food and forestry practices, making historic investments in infrastructure and clean energy capabilities in rural America, and committing to equity across the Department by removing systemic barriers and building a workforce more representative of America. To learn more, visit

Complementary Content