Heyy! I'm new at the tree frog thing and I think I'm screwing up already..

I have 2 beautiful tree frogs, Tiki and Pogo. They both have developed small black sores on their dorsal side. I talked to a vet and he simply told me to try povidone iodine...he has no clue though. Tiki is already going through a dislocated leg and the vet is no help. Can you guys help?

Some info to help:

I use spring water.
Aquarium has moss at the bottom and is kept humid at all times.
Have sterilized dishes.
Tank cleaned regularly.
Fed crickets from pet store.

I hope someone can help! Thanks so much.

Kelsey