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. 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. Real time reverse transcriptase polymerase chain reaction (RT PCR) testing was 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. The RT PCR test is sensitive, specific, and does not cross-react with other coronaviruses of dogs or cats. Testing from both laboratories yielded the same results.
Experts from the School of Public Health of the University of Hong Kong, the College of Veterinary Medicine and Life Sciences of the City University of Hong Kong, and the World Organization for Animal Health (OIE) believe the consistency and persistence of the results suggest the pet dog may have a low-level of infection with the virus. While officials have said this may be a case of human-to-animal transmission, this is still speculative and further testing is being conducted. This pet dog is one of two pet dogs currently 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. Furthermore, 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.