That is strange for sure. I read a few sites that reccomended swabbing severely affected areas directly, maybe that would be the best idea. And yes, frogs are more sensitve than fish since they absorb
everything through their skin. I treated mine with general fish fungus meds at their full dosage and he seemed fine. (he didn't have fungus...just age spots apparently

) Good luck with it, I hope your little guy is ok.
Chrissy