Were Green Eggs and Ham not eaten because they are treif?
Is the Cat wearing a Hat in lieu of a yarmulke?
Did Horton hear a who, lay an egg, and ask why this night is different from all other nights?
These and many other questions will have to remain unanswered, because, despite multiple rumors to the contrary, Dr. Seuss is not a Jew.
He obviously sympathized with the cause, a la inaugural JONJ entry Charlie Chaplin, but that's as far as it goes.
So much for Seuss. A mensch? Certainly. A goy? Undoubtedly.