Yes Geordie have had good tests come back , but I collect the mornings droppings and take a bird in to be tested so everything fresh I'd rather test than give treatments unnecessarily , young birds don't have any immunity that's correct and should be given that from the parents , I can't see how treating the parents actually helps the young birds at all in fact I think it sets them back as parents stripped of vital antibodies in there milk . There are no treatments in nature the birds cope with the stress daily life brings no big queues by feral's at the vets waiting for there junkie fix , birds that are healthy and don't need propping up with meds are always going to breed the healthiest young birds , nature ensures the breeds survival by design and evolution , if your a bird in the wild and your ailing your dead just that in a loft situation a good fancier will speed the end result up .