Many countries have already banned the use of animals in the circus due to their horrendous treatment as shown on countless undercover documentaries, including Earthlings, and other footage.
Workers themselves have quit the industry do to the mistreatment, and complete lack of respect in every aspect of these animals' day-to-day lives. When an unsuspecting person takes their child to the circus it teaches the child that animals are made explicitly for humans' entertainment not to mention a complete lack of respect for the animals.
Many countries in South America, Europe and Asia have banned this already, while other countries are in the process. Hopefully we could be next to see the light and save these creatures who deserve a chance to be Free and Pursue Happiness.