Green frog attacked by a cat

[Charlieamanda]

I have several juvenile green frogs in a kiddie pool the past few months and on the 4th of September one was attacked by a local stray cat.
I was able to save him, but he lost his right leg and can no longer "hop", so I have him inside and will keep him as a pet.
I've had frogs and toads as pets for 10+ years and have nursed dozens of them back to health, but this injury is concerning me bc I'm simply unfamiliar with injuries with this species.
I have him in a small storage bin full of treated water with large rocks on one side.
3 days ago I noticed the "stump" was "fuzzy" and I'm not sure if this is part if the healing process or a serious problem.(see pics)

Any information would be greatly appreciated.
Thanks

[Charlieamanda]

I changed the water yesterday and I can clearly see the skin on the stump has pulled off, so it's exposing muscle and bone.
To my shock he was trying to get away from me, I took that as a good sign since the first few days it did not struggle at all.
The frog overall appears healthy and strong, but is not eating the live crickets I've put in the tank, so I'm going to try some wax & super worms, I know they go crazy for caterpillars, so I hope this will work.
I did notice a definite odor when I changed the water, i routinely do water changes, but the stump looks clean without any redness or swelling.
He's been spending more time on the rocks outside the water and that "fuzziness" is no longer present.

[Charlieamanda]

So yesterday the "stump" sloughe'd off!
I can't tell whether the bone is still present but the muscle and tissues were floating in the container, so I did another water change.
He's still not eating.