The story of the three little pigs was first published in the early 1800's. It was a lesson about wasting time and playing instead of working hard and achieving goals. The two silly pigs were almost eaten by the Big Bad Wolf but managed to get to the house made of bricks and safety.
In 2007 some elementary schools in England changed the story to "The Three Little Puppies",so they wouldn't offend the Muslims.
Muslims consider pigs as unclean. They also consider dogs as being unclean but maybe the schools didn't get that memo.