In other words, we check out how many SARS-CoV-1 animal virus genes are in SARS-CoV-1 human viruses.
One thing to keep in mind is that the SARS-CoV-1 virus dates back some two decades (20 years: The Coronaviridae - 2, Appendix One) so we are finding out that some of these genes haven't changed over that period of time in some viruses.
That applies whether the virus is in an animal or in a human.
The appendices today (Appendix One, Appendix Two, Appendix Three, Appendix Four) have lists of animal viruses, along with their GenBank identity key, and a count of how many genes of those animal viruses are found in human viruses (Appendix Four applies to SARS-COV-2).
The process that produced the appendices is to proceed through 1,500 animal viruses in the SQL database, extract the genes of each one in turn, then search all the human viruses (429 in the same database) for human virus genes matching those genes in those human viruses.
The descriptions "animal virus" and "human virus" indicate where they were extracted ("animal virus" means that it was extracted from an animal meta-host, while "human virus" means that it was extracted from a human meta-host).
The SARS-CoV-1 animal virus and the SARS-CoV-1 human virus can be exactly the same, or be slightly or largely different (in terms of the number of genes in them).
The Dredd Blog hypothesis as to why that reality exists is that the differences are caused by the antibiotic, chemical wars waged against the microbiome of mass-produced-animals-for-food agricultural industry (On The Origin Of The Home Of COVID-19, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21).
The basic dynamic is that the indiscriminate use of antibiotics and other chemicals, as an attempt to react to the poor conditions the animals are produced in, injures and/or kills helpful microbes, thereby damaging the replication machinery in those killed or injured microbes.
This is machinery which is constantly in the process of replicating the genome of the microbe it is located in, as well as the genomes of viruses within the microbe.
The bad results cause the production of mutant (damaged) viruses and microbes alike, which can then become pathogenic (What Did The Mass Extinctions Do To Viruses and Microbes?).