So sorry to hear about your frog. It is possible that he did get his foot caught in the filter. If you look at my photos http://jancy.flippersnfins.yuku.com/album#.UIrrGrSdL8s] I put a little piece of Plastic Canvas (purchased at Michaels Craft Store size 7 mesh) in my filter intake so it wouldn't have such large slots in it. I also thought it would be safer for flippers and debris can still go through instead of using a nylon stocking or filter floss.

If she is still hanging at the top and looks a bit puffy you may want to fast her for a day or two. Is she trying to stay down but floating up? If it's gas she will float like a helium balloon. Not always is it bad that they float though because they do like to relax like that but an unusual amount of floating may be an indication that something is not right.

Definitely do a good 50 - 60% water change with Prime.

Cute Tads!!