I bought two White's Tree Frogs from a local pet store on Dec. 24th. One is very active and a bright green, eats alot (even ate a pinkie mouse) and looks extremely healthy. but i also have a dark brownish green on that is alittle skinnier that isnt active at all. when i saw it at the pet store, it was very inactive (should have paid attention to this when i got it). Ever since i got it, its always been hiding and only comes out to go into it's water bowl. For the first two weeks i had it, it wouldn't eat anything so i resorted (sadly) to force feeding it mealworms. three weeks ago, i noticed that it's left arm was extremely bloated and there was a bump on it's back. eventually, the bump poped and there was a clear orangish liquid oozing out of it. yesterday, all that was left of it was an open wound. today, it;s still an open wound but next to it, is an even bigger bump with alot of liquid inside of it. i dont know what to do because my parents dont want to pay for it if i take it to a vet. the green frog is still pretty active and has quiet an appitite.

what should i do about my brown frog? i still dont know what's up with it's arm and i'm really worried. this is the first time i've ever had a frog for a pet. how much might it cost if i do take it to a vet?