It's his eye this time. I noticed on Thursday that under his left eye looked red and, on closer inspection, found what looks like a scratch on his lower eyelid. I phoned the vets on Friday and they told me to keep it clean so we've been bathing it in diluted hibiscrub. It seemed to be OK but this morning it looks puffier and DH thinks he has seen what looks like white pus on it (I'm at work so will be checking later!).
I've got him an appointment this evening but I'm really regretting not taking the poor little chap Friday evening or Saturday morning. He's been fine in himself, eating normally and chasing his imaginary friends so I didn't want to drag him off unnecessarily.