Animals and SARS-CoV-2: Species susceptibility and viral transmission in
experimental and natural conditions, and the potential implications for
community transmission.
Abstract
The current COVID-19 global pandemic, caused by severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) of probable bat origin, has
highlighted the ongoing need for a One Health response to emerging
zoonotic disease events, which are significantly increasing over time.
Understanding the human-animal interface and its relevance to disease
transmission remains a critical control point for many emerging
zoonoses. Determination of the susceptibility of various animal species
to infection with SARS-CoV-2 and the role of animals in the epidemiology
of the disease will be critical to informing appropriate human and
veterinary public health responses to this pandemic. A scoping
literature review was conducted to collect, evaluate and present the
available research evidence regarding SARS-CoV-2 infections in animals.
Experimental studies have successfully demonstrated SARS-CoV-2 infection
and transmission in cats, ferrets, hamsters, bats and non-human primates
under experimental settings. Dogs appear to have limited susceptibility
to SARS-CoV-2, while other domestic species including pigs and poultry
do not appear susceptible. Naturally occurring SARS-CoV-2 infections in
animals appear uncommon, with 14 pets, 8 captive big cats and an
unreported number of farmed mink testing positive to date. Infections
typically appear asymptomatic in dogs, while clinical signs of
respiratory and/or gastrointestinal disease tend to be mild to moderate
in felines, and severe to fatal in mink. Most animal cases have been
infected by close contact with COVID-19 patients. In domestic settings,
viral transmission is self-limiting, however in high density animal
environments there can be sustained between-animal transmission. To
date, two potential cases of animal-to-human transmission are being
investigated, on infected mink farms. Given the millions of COVID-19
cases worldwide and ongoing potential for further zoonotic and
anthroponotic viral transmission, further research and surveillance
activities are needed to definitively determine the role of animals in
community transmission of SARS-CoV-2.