The phlegm is clear. It's all foamy. It's not much fun cleaning mouthfuls of it off the carpet at 6am ! Or trying to get to him to wipe his mouth so that he doesn't shake it all over the furniture! The poor little guy seems to always try and swallow it down again, as opposed to getting rid of it, which most likely prolongs the coughing.

He had a lung xray, swab and flush a couple of months back when this first reared it's head. The vet sent samples off, and came back saying it was a particularily virulant type of KC. It then cleared up again, before coming back with a vengence this past couple of weeks.

I'll try and video him on my phone tomorrow morning so that I can show it to the vet on Friday, maybe she doesn't believe me about how bad it is.

Thanks everyone for their advice and concern. It's reassuring to have so many caring people on here.