Hi, I have a horned frog and it is doing very well. However, everytime I go to a pet shop I see so many of them that have mouths that are constantly open/cannot close. I understand that some are because of calcium deficiency and their lower jaw bones become deformed. But some even with normal shaped lower jaws seem to have their mouths a little open all the time and unable to close. Does any one know why this is and how to prevent it?