COVID-19: domestic animals play no part in transmission of the virus to humans
When asked about potential transmission of the COVID-19 disease via domestic animals, ANSES urgently convened an expert group to answer this question. It issued its first opinion on 9 March 2020. The recently acquired initial findings of investigations into the possible infection of pets during COVID-19 outbreaks and experimental inoculation models of certain domestic animal species have since led the Agency to update its expert appraisal. In particular, there have been reports of sporadic cases of contamination of domestic animals, and experimental infections have demonstrated the susceptibility of some animal species (ferrets, hamsters and to a lesser extent cats) to the virus. After taking this new information into account, ANSES nevertheless considers that there is currently no scientific evidence showing that domestic animals (livestock and pets) play an epidemiological role in the spread of SARS-CoV-2.
Since the SARS-CoV-2 coronavirus – responsible for the COVID-19 disease – emerged in China in December 2019, the knowledge acquired has shown that its main route of transmission is human-to-human, through contact between people or inhalation of infectious droplets emitted when they sneeze or cough.
Nevertheless, because the virus's genetic structure indicates that it probably originated in animals, ANSES was asked to examine the potential role of domestic animals in virus transmission. Following the urgent mobilisation of its expert group, the Agency produced its first opinion on the subject on 9 March 2020. This was updated on 15 April 2020 in light of the new scientific knowledge available.
With regard to possible transmission of the virus by domestic animals (livestock and pets), the conclusions of the expert group indicate that:
The findings of the first experimental animal infections published since 9 March show that:
- pigs and poultry (chickens and ducks) were not susceptible to SARS-CoV-2 under the conditions of the two trials conducted in China and Germany;
- were found to have low susceptibility to the virus under the experimental conditions of the only study published by Chinese researchers;
- young cats were receptive to the virus, based on the results of the only experimental trial available. This trial identified respiratory tract lesions following infection in a young cat and transmission of the virus from the infected cat to one of the contact cats (a cat living in the same enclosure but without direct contact with the infected cat);
- in the three experimental studies published, ferrets were susceptible to the virus and developed clinical signs and respiratory tract lesions following infection. There was also proven transmission of the virus to contact ferrets. The same was true for hamsters.
There have been reports of rare cases of contamination and/or natural infection of pets with SARS-CoV-2, following close contact with their owners who were themselves infected with COVID-19. These cases remain sporadic and isolated in view of the high level of virus circulation in humans and the scale of the current pandemic.
In conclusion, in the current context and in view of the available information, ANSES considers that there is currently no evidence that domestic animals (livestock and pets) play an epidemiological role in the spread of SARS-CoV-2. Moreover, no cases of contamination of humans by pets have been reported to date.
Nevertheless, ANSES reiterates the need to prevent pets from coming into close contact with sick people, to follow basic hygiene measures when in contact with a pet (washing hands before and after stroking it and after changing cat litter), and to apply "barrier gestures" in any situation.