Sorry to be late in on this one: had to laugh as our cat's name is pronounced Mishka too (though the spelling's a bit different!)
In Polish, Myszka means "little mouse" (Mys being mouse) and so if you ever look for Beatrix Potter translations, Mrs. Tittlemouse (littlemouse) becomes Myszka :-)
Ours was named by a Polish friend, as she squeaked rather than miaowed as a kitten (and it's still a very high-pitched miaow after 14 years...)
:-)
moonbells