Vet : Hi there, vet Andrew here. Are you at your computer?
Vet : You've been very good to help this cat out, and lucky that he's let you examine him! Many cats are not so lucky. Has there been any change in the leg since he's been lame on it, e.g. swelling or discharge?
Vet : If he's still not putting weight on it, that means it's either causing him pain, or there's been some nerve damage. Does he carry the leg pointing slightly backwards, or is it floppy?
floppy and perhaps slightly twisted to the left
Vet : If you're absolutely sure there's no bones broken - which can be found with careful examination as you've already done - then the likelihood is that he's had a fall and damaged his radial nerve, and the leg is paralysed. This would explain the lack of pain or obvious injury. This nerve has a good regenerative ability, and he may well recover over a matter of months. You may see the leg muscles on that side wasting slightly over the coming weeks.
Vet : If it is radial paralysis, there's really nothing you can do but wait. However, seeing as we can't be 100% sure, I would pop in to your regular vet's and explain the situation. In these cases, I am often happy to give out some antibiotic and pain relief that can be put in food for feral cats, as it is usually impractical to catch and bring them in.
Vet : This way you can be sure you've done everything you can for him.
Vet : Do you have any further questions?