This question is about a senior-age cat (10-11, not sure of exact age as she was a stray) with no relevant medical history. She had a "fall from height" ~3 years ago with fractured (?) roof of mouth but has been fine since receiving treatment then.
She does seem to be thinner these days despite eating enough, but this has been going on for a while.
3 days ago she was fine when we came home from work. We went out again to do other stuff and when we came back in the evening, noticed that she was limping on the right back leg.
She is putting weight on it (not holding it up off the ground) on every step, it isn't "floppy". We have examined the paw, claws, pads etc and found nothing - there isn't anything inflamed, sores, bites, abscesses, lumps or anything like that either. She is still climbing stairs (a bit more awkwardly than usual though) etc.
From what I can tell she isn't in particular pain with it from any of the "poking" I tried (paw pads etc), she didn't pull the leg away or anything like that. But it must be painful to put full weight on it since she isn't doing that...
She is eating, toileting, interacting with our other cats normally.
I'm sure it is something physical rather than e.g. acting out "behaviourally".
It seems to come and go a bit in that sometimes she is limping more than others so I think it's "better" and then later she is limping a bit more etc.
My questions: - would you advise taking her to the vet at this point or wait a bit longer and see if it resolves? - what are possible causes of this given that we've ruled out the usual "injury to paw pads" etc. ?
Update:
I waited another day and then made an appointment at the vet for the next day, so about 5 days total since the limping started. During this time it didn't change in any way and her habits (eating, toileting, amount of activity etc) were still normal.
The vet did a physical exam (but no x ray at this point) and didn't find anything so it could be arthritis or just "pulled something" etc.
We now have a Metacam anti-inflammatory to give her daily and instructions to go back after this is finished if it still continues (at which point they will probably do x rays etc)
The vet also recommended some blood tests to check for various conditions, which I'm pleased to say have come back normal!