This morning 3 of my 16 girls emerged from the coop with what I can only describe as wheezing! Some sneezing from two of them and another seems to be coughing (can chickens cough?). One of the two that is sneezing also has a hoarse voice -- her egg song today sounded like a raspy jazz singer with a bad case of laryngitis. I suspect a respiratory issue and I scoured the web for treatments. I came across a product called Respite. But it seems it's not available in the US, only in the UK. Is there an alternative remedy or comparable product I should try?