I'm sorry to hear that he's so sick. I'll keep him in my thoughts and prayers.

My Sky was diagnosed with mild asthma last year and he was on pred and another medicine for several months to get him through the worst months. He would get sneezing and coughing attacks but I never saw him throw up any white foam. My vet said that when it's cold and damp outside that this usually makes asthma worse. He's had a few mild fits this year but nothing like he did last year.