A member in our club had this last year and its a varient of paramyxo! Firstly started in youngsters, by the time he'd lost half the team he killed the rest because a vet had diagnosed YBS and they were getting wrong treatment. Then it moved into his yearlings which had been jabbed the previous season so again killed the lot, burnt all interior fittings in the loft, flooded the place with virkon-s. Thinking the problem was gone it then started in his stock loft at his own house (his race loft is in his fathers garden). Again it was suspected to have come in on a couple of new youngsters.
Wattle, have any started dieing yet?
It is a lesson learned here, never mix or introduce birds from different sources until you have quaranteened for 7 days!
Is this not also what went through the Scotland one loft race last year?