Originally posted by kuhio98
I absolutely disagree with the idea of rehoming it based upon YOUR assessment (or the assessment of anyone) as to whether they are taking adequate care (as you see it) of the cat.

I see nothing wrong with getting the kitty some medical attention, but don't assume you know the whole story and that abuse and neglect are involved.
Rest in Peace Kuhio

I both totally agree with what you said but I don't think it applies in this particular situation.

I wouldn't assume a cat that was very thin (My Treacle), very scruffy (Georgie at times) or other problems were being abused.

I would do what you suggested and contact the owner after a vet visit.

But in this case the cat has a clear visible injury which the owner has either ignored or not noticed, both options stem from neglect on the owners behalf

Maybe the prudent thing would be a vet visit, followed by talking to the RSCPA people about the situation ?