As revealed by director Ken Annakin on the DVD commentary, the trapped zebra was subjected to electric shocks to make it move about, a practice that is now illegal in Hollywood movies.
On the DVD commentary, director Ken Annakin said the man that the tiger is chasing in the scene with the fight with the pirates was actually the trainer of the tiger. The trainer, knowing how hard tigers are to train, and with the man having his back to the tiger would make the tiger naturally predatory, he could not trust the tiger to not maul the actor playing the pirate.
Sir John Mills was felt to be out of place, as he was English, and the rest of the family were played by Americans.
Many of the animal scenes would not be allowed in a movie today, due to laws governing the use of animals in movies.