According to The world health organization scientist suspected cats were to blame.
Thousands of cats have come down with viruses throughout the United States shelters after HSUS transport of cats in from CHINA 620 ill cats from the Chinese markets were brought into the United States and The United Kingdom right before the outbreak of the coronavirus.
SARS-CoV, MERS-CoV and SARS-CoV-2 –Jumped to the human population. Before 2003, only two coronaviruses (HCoV-229E and HCoV-OC43) were known to infect humans.
To date, seven coronaviruses have been shown to infect humans. Common human coronaviruses Betacoronavirus HCoV-OC43 and HCoV-HKU1 as well as Alphacoronavirus HCoV-229E and Alphacoronavirus HCoV-NL63.
In early 2003, outbreaks of severe acute respiratory syndrome (SARS) occurred in southern China, and then spread to other parts of the world.
http://jtd.amegroups.com/article/view/1246/html
Deadly Viruses That Hopped Across Species
https://www.livescience.com/12951-10-infectious-diseases-ebola-plague-influenza.html