Anthrax has been found in parts London where cattle was kept at the time of one of the outbreaks. Can’t remember which one. That being said, I am somewhat dubious of these theories but some experts studying the science believe otherwise. I don’t think the possibility can be so quickly dismissed.
In the Middle Ages, wool was a major industry, and anthrax was probably something of a common problem.
But that has nothing to do with the Ebola virus.
The running water and sewer systems of Rome kept diseases down for several centuries.. when those ended Europe was at risk.