My dog is hackin [sounds like coughing] and throws up white foam. I live in CT, and I don't take him out. My sister does. I don't know if she clothes him or anything. Maybe not. I think he ate something or maybe he's just sneezing since that's what it sounds like. Any ideas what this is? He throws up white things and sometimes clear things that has foam in it, and sometimes he swallows it up again. I don't know what's happenin to him.