I beg to differ...croup is EXTREMELY contagious, and can be very dangerous. My son lost consciousness from lack of oxygen as a result of croup. His oxygen saturations were so low that he was hospitalized for four days and placed on a nebulizing mask.

If a child has a barking cough and is struggling for air (that's what that hoarsness sound was when he was breathing in air), one should treat this as an emergency, and insist that his parents come immediately. It means his airway is compromised. If, for whatever reason they don't come and get him, I would transport him to a hospital myself. It is my firm belief that whenever a child is having breathing issues, there is no such thing as an overreaction.

I would not accept the child back into care until he had doctor's clearance. But...hindsight is 20/20 as they say. As for how to go about it, you just say so. "I am sorry, I am uncomfortable accepting DCK back into my care until he's been seen and cleared by a doctor, and I'm going to need confirmation of that in writing. I'm sorry, but I have other children to think about, and I'm sure you'd appreciate the same if it was another DCK".