Thanks guys..
Mark..
carpet is shag pile wool or wool mix. I do pre-vac, pre-spray & agitate, of course! It was just bit damp, did plenty of dry strokes, was almost dry before i left. My machine is a steemeasy 400
Derek..
They have a dog indeed.. 2 in fact. Lots of dog hair & pee. Whats oil & dander? from the skin of the dog? Although it was more brown than red. on the part that wasnt dirty, it seemed to have just darkened/dulled the colour (im not talking about a huge area here just a few square feet, i stopped rather than continue!)
Possibly just really ground in dust/dry soil then? Doesnt easily move by dry vac!? I'll thoroughly vacuum again and extract again and see how it goes. If no joy I'll try the rotary..