Three lions are among eight big cats at the Bronx Zoo found to have contracted the virus that causes COVID-19. The lions pictured appear in an episode of "The Zoo," an Animal Planet series about the Bronx Zoo.
Two domestic cats in New York and seven more big cats at the Bronx Zoo are confirmed positive for SARS-CoV-2, the virus that causes COVID-19 in humans.
The findings were shared separately by the U.S. Department of Agriculture, World Organisation for Animal Health (OIE) and the Bronx Zoo.
The household cats are the first pets in the U.S. to test positive for the virus. The animals are from different parts of the state, according to a statement issued today by the USDA Animal and Plant Health Inspection Service (APHIS).
Now recovered, both cats were tested for SARS-CoV-2 after presenting to veterinarians with signs of mild respiratory illness. One cat belonged to a person who had tested positive for COVID-19. The other cat came from a household where no one else was confirmed infected. How that cat contracted the novel coronavirus is unclear. "The virus may have been transmitted to this cat by mildly ill or asymptomatic household members or through contact with an infected person outside its home," the USDA offered.
Both cases were uncovered earlier this month by Antech Diagnostics, one of two commercial veterinary reference laboratory chains known to be actively surveilling for SARS-CoV-2. Every feline and canine sample sent to Antech laboratories for routine gastrointestinal or respiratory PCR analysis is tested for SARS-CoV-2 also, explained Dr. Jennifer Ogeer, Antech vice president for medical affairs and commercial marketing.
"As of early March until today, we've done over 2,000 samples in the surveillance testing from dogs and cats, most from the United States and some from Canada," Ogeer said. "Our goal has been to detect emergent virus so we can learn the frequency of the virus's transmission from humans to animals."
If Antech finds a presumptive positive, government protocol directs that they contact the USDA, which performs testing at its National Veterinary Services Laboratories in Ames, Iowa. If the positive result is confirmed, the USDA contacts relevant public health authorities. The chain of command restricted Antech from publicizing the results before today, Ogeer said.
Despite infection by the novel coronavirus in the two house cats, USDA and the U.S. Centers for Disease Control and Prevention continue to maintain that there's no need to routinely test companion animals for the virus. (While Antech restricts its SARS-CoV-2 test for surveillance, Idexx Laboratories recently made its test for the virus commercially available to veterinarians.)
"Public health officials are still learning about SARS-CoV-2, but there is no evidence that pets play a role in spreading the virus in the United States," the USDA statement reads. "Therefore, there is no justification in taking measures against companion animals that may compromise their welfare. Further studies are needed to understand if and how different animals, including pets, could be affected. … At this time, routine testing of animals is not recommended."
If other animals are confirmed positive for SARS-CoV-2, the USDA said, the findings will be posted on its website.
Developments at the Bronx Zoo
The first known case in the U.S. of an animal developing COVID-19 was a 4-year-old Malayan tiger at the Bronx Zoo, named Nadia. The zoo announced her case on April 5.
The zoo reported that day that six other inhabitants — Nadia's sister, Azul; two Amur tigers; and three African lions — likewise had developed a dry cough. However, authorities opted not to test them at the time because "collection of diagnostic samples in big cats requires general anesthesia," according to a statement by the USDA. "Since all tigers and lions were exhibiting similar respiratory symptoms, the attending veterinarian felt it was in the best interest of the animals to limit the potential risks of general anesthesia to one tiger for diagnostics."
All of the big cats with clinical signs were presumed to have COVID-19. Now, that's been confirmed.
The latest developments at the Bronx Zoo initially were reported by the World Organisation for Animal Health in France, known as the OIE. The OIE posted a report dated April 17 from Dr. Mark Davidson, associate administrator of USDA APHIS, confirming a second zoo case.
The post reads: "One of the three previously reported exposed lions at a zoo was confirmed positive for SARS-CoV-2/COVID-19 on 15 Apr 2020. This follows the initial report of a tiger confirmed on 4 Apr 2020."
Asked by the VIN News Service today about the OIE report, Bronx Zoo officials responded with a press release indicating that a total of eight big cats — Nadia, four other tigers and three lions — have now tested positive for COVID-19.
The subsequent testing, "was done by using a fecal sample test developed by our laboratory partners that does not require the animals be placed under anesthesia," the press release says. "The fecal tests confirmed our suspicion that all seven cats had the infection, and also determined that one tiger ... that never developed a cough was also positive for the disease."
The zoo reports that all eight cats are doing well: "They are behaving normally, eating well, and their coughing is greatly reduced."
The press release also notes that all of the tests were conducted in veterinary laboratories "and resources used did not take from those being used for human testing."
In all cases, the cats are presumed to have contracted the virus from an infected person, believed to be an asymptomatic or pre-symptomatic zookeeper. No individual has been identified as the source, however. The Bronx Zoo has been closed since March 16.
Outside of the U.S., two dogs and two cats have tested positive, as well, all belonging to owners positive for COVID-19. The dogs and one of the cats were in Hong Kong. The second cat was in Belgium. Of the four, only the pet in Belgium was said to have clinical signs consistent with COVID-19.