Again, I wouldn't be overly concerned by the report of 1 dog having covid-19 virus even if he has disease. If this was a true zoonotic disease that affects both dogs and humans, we would have seen similar epidemic among dogs in China and reports of other outbreaks in dogs around the world would be present.
It is rare, but not unusual to see abberant infection/infestations with species that are not the target host. These are almost always mild, abnormal, dead end situations. Often times the affected individual has a compromised health status.
The one that comes to mind is Heartworm in people. It usually presents as a spot in the lungs that looks like a tumor. Upon surgical removal a heartworm larva is found. Unusual, but does happen.