Should you quarantine the dog? Disinfect the cat? When a Pomeranian in Hong Kong tested positive for SARS-CoV-2 last week, pets soon became part of the coronavirus conversation. The case raised the possibility that pets could become part of the transmission chain for coronavirus, however, many questions remain about this possibility and how best to respond. The following information comes from the American Veterinary Medical Association (https://www.avma.org/resources-tools/animal-health-and-welfare/covid-19). (Updated as of March 14, 2020):
Q: Hong Kong’s Agriculture, Fisheries, and Conservation Department (AFCD) has indicated that a pet dog whose owner had contracted COVID-19 had been tested for SARS-CoV-2 and that multiple tests over several days’ time had come back “weak positive.” Is there more information and should we be worried for our pets or for ourselves?
A: The ACFD first collected samples from the pet dog, reportedly a 17-year-old Pomeranian, on February 26 and detected low levels of SARS-CoV-2 material in samples from its nasal and oral cavities on February 27, using a real time reverse transcriptase polymerase chain reaction (RT PCR) test. The RT PCR test is sensitive, specific, and does not cross-react with other coronaviruses of dogs and cats. The ACFD repeated the test on February 28, March 2, and March 5 with continued “weak positive” results (nasal and oral sample, nasal sample, nasal sample, respectively). “Weak positive” suggests a small quantity of SARS-CoV-2 RNA in the samples. It doesn’t distinguish whether the samples contain intact viruses, which are infectious, or only fragments of the RNA. To better understand what this finding means, additional testing has been, and continues to be, conducted. Part of that testing is serology to see if the dog is mounting an immune response to the virus. An acute phase sample was negative, indicating there are currently not measurable amounts of antibodies to the virus in the dog’s blood. This does not mean the dog is not infected with the virus, because it is not uncommon to have a negative result in earlier stages of infection. It can take 14 days or more for measurable levels of antibodies to be detected. Hong Kong officials advised that a second “convalescent” phase sample will be obtained later for further testing. In addition, gene sequencing of the SARS-CoV-2 virus from the dog and its close human contacts has been done and the viral sequences are very similar. Experts from the School of Public Health of the University of Hong Kong and the College of Veterinary Medicine and Life Sciences of the City University of Hong Kong believe the consistency and persistence of the results suggest the virus may have spread from the infected people to the dog in this particular case. Follow-up serology is pending. Testing has been conducted by the laboratories of the AFCD and the School of Public Health of the University of Hong Kong. The latter is an accredited reference laboratory for the WHO for the testing of SARS-CoV-2. This pet dog is one of two pet dogs under quarantine in separate rooms in a facility at the Hong Kong Port of Hong Kong-Zhuhai-Macao Bridge; the second pet dog has had negative results of tests for the virus. The pet dogs are being cared for and neither has shown any signs of being ill with COVID-19. In other testing, IDEXX announced on March 13 that it had evaluated thousands of canine and feline specimens during validation of its new veterinary test system for the COVID-19 virus and had obtained no positive results. The specimens used for test development and validation were obtained from specimens submitted to IDEXX Reference Laboratories for PCR testing. Considering this information in total, infectious disease experts and multiple international and domestic human and animal health organizations agree there is no evidence at this point to indicate that pets can spread COVID-19 to other animals, including people.
Q: Can SARS-CoV-2 infect pets and can it be spread by pets to other animals, including people?
A: We do not have a clear answer as to whether SARS-CoV-2 can infect pets at this time. That said, currently, there is no evidence that pets become sick. Infectious disease experts, as well as the CDC, OIE, and WHO indicate there is also no evidence to suggest that pet dogs or cats can be a source of infection with SARS-CoV-2, including spreading COVID-19 to people. More investigation is underway and, as we learn more, we will update you. However, because animals can spread other diseases to people and people can also spread diseases to animals, it’s a good idea to always wash your hands before and after interacting with animals.
Q: Can pets serve as fomites in the spread of COVID-19?
A: COVID-19 is usually primarily transmitted when there is contact with an infected person’s bodily secretions, such as saliva or mucus droplets in a cough or sneeze. COVID-19 might be able to be transmitted by touching a contaminated surface or object (i.e., a fomite) and then touching the mouth, nose, or possibly eyes, but this appears to be a secondary route. Smooth (non-porous) surfaces (e.g., countertops, door knobs) transmit viruses better than porous materials (e.g., paper money, pet fur), because porous, and especially fibrous, materials absorb and trap the pathogen (virus), making it harder to contract through simple touch. Because your pet’s hair is porous and also fibrous, it is very unlikely that you would contract COVID-19 by petting or playing with your pet. However, because animals can spread other diseases to people and people can also spread diseases to animals, it’s always a good idea to wash your hands before and after interacting with animals; ensure your pet is kept well-groomed; and regularly clean your pet’s food and water bowls, bedding material, and toys.
Q: Is there a test I can use to check my pet for SARS-CoV-2?
A: IDEXX announced the availability of a test on March 13, but neither the CDC, AVMA, nor IDEXX is recommending that pets be tested at this time. In announcing the availability of their test, IDEXX indicated that thousands of canine and feline specimens had been evaluated during their validation of the test and none had come up as being positive. These results align with the current expert understanding that COVID-19 is primarily transmitted person-to-person and supports current recommendations against testing pets for the COVID-19 virus. Dogs or cats with respiratory signs should be evaluated by a veterinarian for more common respiratory pathogens before looking to evaluate them for COVID-19. It’s important to remember that there is currently limited evidence that pets can be infected with SARS-CoV-2. There is no evidence to suggest that pets can spread COVID-19 to other people or other pets.
If you have questions about COVID-19 and how it may affect your pets, please contact us!