Nonsense! When I was a kid -- I was a WDW fan even then -- I did one of my major term papers on the life of Walt Disney. I read lots of books about him and in his childhood, he had a pet mouse that he later based some VERY popular cartoon characters on! I think the mouse's name was Mortimer, but it's been a while since that 8th grade paper!
Yes...I recall reading that, while maybe not afraid of mice, that Walt did not like mice. So it is greatly ironic in that "it all started with a mouse"... Mortimer was Walt's original name for Mickey but Lillian didn't like it so Motimer became Mickey...