I had PLF shortly after starting back in the doo's 4 years ago! had all the symptoms ie - flu like feeling at night when been in loft all day, loss of weight, very bad coughing and out of breath all the time !! had blood test taken at blackpool show which confirmed I had a high allergic reaction to pigeon protein (bloom) so I arranged to see a specialised docter in Aberdeen who performed more tests/scans (I thought he was defo going to tell me to get rid of the birds) and the out come was he was happy that I had contacted him early and the damage to my lungs was minimal and as long as I found a mask (also coat/hat) that I could wear in the loft at all times that works there was no reason to get rid of the birds !! so that's exactly what I did and I have had no problems since then whatsoever !! PS.He also stressed not to use the white paper masks as they were no use for pigeon bloom !!