The worst phase for the black cats came after Egyptian dominance.
This could be probably due the later rulers that shunned everything that was Egyptian. As breaking the cultural shield is the first route to setting up a new dominance, later empires might have tried to break the belief system and thus induce new hatred which later, through generations, transformed into superstitions.
The origins of this old superstition can be traced back to ancient Egypt, where the Goddess Bast was represented as a black cat. People began to fear black cats because they associated them with the Goddess getting angry with them and causing problems.
Black Cat Myth: Variations Across Geography
Depending on the place one stays, there are various superstitions pertaining to the cats. While in USA or several European countries, a black cat crossing your path is considered unlucky, in places such as Britain and Japan, it is considered lucky.