When I use the drop down menu to train my pet Belgora, it will not show Health. So it's forcing me to train her on the other options. All the other pets (31 in all) will show health in the drop down menu.

This is because Belgora already has 2.5 times as much health (251) as her level (100).

Thank you! I was informed earlier about this. :) I went ahead and trained her in Level.