Since the initial outbreak of SARS-CoV-2 and COVID-19, there have been numerous reports of animals becoming infected with the virus. There’s still a lot to learn about how SARS-CoV-2 affects different animal species, but the primary domestic animals that have been infected are cats and dogs. Non-domestic animal species have been diagnosed with SARS-CoV-2 infection as well. Overall, evidence suggests that infected animals pose little risk to humans, particularly when appropriate personal protective equipment is used.
In the U.S., for any animal that tests positive for SARS-CoV-2 at a private or state laboratory, USDA's National Veterinary Services Laboratories performs additional testing to confirm the infection and reports the results online. The World Organisation for Animal Health (OIE) also tracks cases in animal species around the world.
SARS-CoV-2 in pets and other domestic animals
COVID-19 is the disease that people get from being infected with the severe acute respiratory syndrome coronavirus 2 (or SARS-CoV-2). Domestic animals do not get COVID-19 like humans do, but under natural conditions, pet cats—and, to a lesser extent, pet dogs—may, although rarely, become infected with SARS-CoV-2 after close and prolonged contact with an infected person. In other words, a person with COVID-19 might transmit the virus that causes this disease to pet cats and dogs (and perhaps pet ferrets and hamsters) in the same way we might transmit it to another person.
Cats and dogs are not easily infected under natural conditions, and there is limited evidence that infected cats or dogs spread the virus to other animals. However, a single case report from Thailand suggests that infected cats could spread the virus to people when inadequate measures are taken to prevent transmission. In that report, a veterinarian was suspected to have been exposed to the virus when a SARS-CoV-2-infected cat sneezed in her face. The veterinarian, although wearing an N95 mask at the time, was not wearing a face shield or protective eye wear.
SARS-CoV-2 in farmed, captive, and free-ranging wildlife species
In 2020, various cases of infections in farmed mink were reported in multiple countries. It’s likely mink were originally infected by farm workers with COVID-19 before transmitting the virus to other mink. Evidence also suggests mink-to-human transmission in rare cases.
In addition, captive big cats (e.g., lions, tigers, pumas, snow leopards) and non-human primates (e.g., western lowland gorillas) from individual zoos or wildlife refuges in the U.S. and other countries have been confirmed infected with SARS-CoV-2. In each case, animals were tested after one or more developed mild to moderate clinical signs of respiratory disease with, in some cases, mild lethargy and loss of appetite. Based on the similarities between the genomic sequences of the virus infecting these big cats and gorillas and those of the virus circulating in nearby human populations, these captive wild animals likely became infected following contact with one or more animal caretakers with suspected or confirmed COVID-19. However, subsequent transmission of SARS-CoV-2 from the first infected animal to other animals housed together or in close proximity cannot be ruled out. Other captive animal species have also been found to be infected—though less frequently than big cats and non-human primates—likely through contact with infected caretakers.
SARS-CoV-2 infections have also been reported in white-tailed deer, both wild and captive, in the U.S. and Canada. Infection and transmission routes among white-tailed deer are not yet well understood, but there are no reports of clinical illness associated with SARS-CoV-2 in the deer populations surveilled. There is also no evidence that deer transmit the virus to people.