SARS-CoV-2 Infection in Dogs and Cats: Facts and Speculations

The recent pandemic caused by the novel human coronavirus (CoV), currently referred to as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which is responsible for COronaVIrus Disease 2019 (COVID-19), is leading to alarmism among pet owners as a consequence of few case reports of SARS-CoV-2 infection in dogs and cats. COVID-19 emerged in December 2019 in Wuhan City, Hubei Province, China, in humans exposed to wildlife at the Huanan seafood wholesale market, the largest seafood market in central China. This is a typical Asian wet market, where different species of farm and wild animals are commonly sold dead and live. The blood and other body fluids originating from these animals represent an exceptional source for the spillover of animal viruses (1). SARS-CoV-2 recognizes a probable zoonotic origin, since the virus likely descends from a bat betacoronavirus, strictly related to the one responsible for the 2002–2003 SARS epidemic (SARS-CoV), which was transmitted to humans directly or through previous adaptation to a not yet identified intermediate host (1, 2). After this adaptation to the new host, the virus was able to spread to the human population through a human-to-human transmission, without any further role of animals in the epidemiological chain. However, pets have been alternatively brought into play as a possible source of infection for humans, intermediate hosts for SARS-CoV-2 transmission to humans or hosts of animal CoVs that may cross-protect humans against the highly pathogenic CoV. The aim of this opinion article is to define the role of dogs and cats in the SARS-CoV-2 epidemiology in the light of current knowledge.