[Baz]

Those who say this is a terminal injury are just guessing. An exam by a vet is the only sure way to know.

Sometimes a leg injury will heal on it's own.

These are called "sprains". Even humans get them sometimes.

If it were me I would wait a couple weeks and see if it does heal on it's own. In the meantime I would call my vet and ask his opinion.

If the injury does not heal in 2 weeks - then you could trap him and take him in for a diagnosis, after which you could make an intelligent and more informed decision....which is what the cat deserves.

My 2 cents...good luck!