It's normal, just about all small dogs do it...at least that's what my vet told me. He said it was sort of like having sinus drainage and that reverse coughing thing they do is how they clear it. Chico did it several times a day, usually in his sleep or just after waking up, when he was younger. Now at almost 6mo he seldom ever does it at all.
Scarey sounding, isn't it?
Scarey sounding, isn't it?