I have a gray treefrog that has a severely swollen forelimb. I'm thinking it maybe an infection or a broken limb. What do I do in this case?

I noticed it today when he was not climbing on the glass, which is where it normally is. It sits on a branch in the vivarium now. Whenever it moves it avoids using that forelimb and the forelimb des not move.

He is also housed with 2 green treefrogs and an Arizona Tiger Salamander. He receives 12 hours of day/night and crickets weekly (a large portion about 2 dozen between the animals) and crickets that I find sporadically in the house.

I'm thinking of removing him from his tank and putting him in a separate aquarium. None of the other critters show similar/any symptoms.

I know that there are different opinions on mixing different species. I am not interested in hearing about these opinions. I just want any advice possible.
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10 Leopard Geckos 3.7.0**
1 Tokay Gecko 1.0.0*
2 Ball Pythons 2.0.0*
1 04 Nicaraguan Red Tail Boa 0.1.0
2 Black Kingsnake 1.0.1*
4 Baird's Rat Snake (Thanks Vadoni!) 2.2.0
***1.0 Loma Alta***1.2Hawkeye 04 stock***
2 Gray Ratsnakes 0.1.1
1 04 Amel Cornsnake 0.1
1 04 Anery Cornsnake 1.0
4 Dekay's Snake 0.1.3**
1.0 Ambystoma tigrinum nebulosum*
1.1 Green Tree Frogs (H. cinerea)*
1.0 Gray Tree Frog (H versicolor)*
0.1 Eastern Box Turtle

0.0.1 Red Milk
1.0.0 Mexican Black/California King Hybrid (Missing)
1 Leopard Gecko 1.0

*indicates possible breeders
**have bred