Also, if I were you , I'd be making some calls to see who will do some testing for you. Blood, stool sample, vet, something. Unless you identify what it is, you're llikely to lose birds. You said your birds had respiratory symptoms; another suggestion...go into the coop when they are asleep at night, and see if you hear them making weird, rattly breathing noises. Again, that's a classic symptom of ILT, but can also be a result of other respiratory problems.