The 37-year-old man, identified only as Torsten F., said he threw the fluffy black-and-white tomcat called Popeye to its death in a fit of anger because it had soiled the apartment, Bild newspaper reported.
"I just blew a fuse," he told the court in Berlin's Tiergarten district.
But Judge Monica Pelcz ruled that an example had to be set. "This was an incredibly brutal act towards a helpless animal... People have to realize that they are not allowed to take out their anger and frustration on those weaker than themselves," she said.