Why Is My Dog Coughing Mucus My Dog Has Kennel Cough, Now He Is Coughing/gagging Up White Mucus,he Has Been Taking The Meds, Normal?

My dog has kennel cough, now he is coughing/gagging up white mucus,he has been taking the meds, normal? - why is my dog coughing mucus

Is this a normal cleaning, what else in his chest for my dog when I was present for HES puppies 3 times now and still a bit of a cough i wouldnt concern only way to clear your chest.