A couple days ago my rhode island red hen had rattly breathing, sneezing, etc. ! I used vet rx & a couple days later she is back to her old self. But this morning I went to let them out and my andalusian hen has this! Her beak and wattles looked slightly crusty too. Her breathing is loud. I started her on Vet RX. What exactly is this? Is it just a cold, or a virus or what? And how did my first chicken get it? Please help!