
i would say it could be either one of them,my friends feild,had kc for a month over christmas and my first flatcoat had a heart murmour which he cough to get the fluids off his lungs,i hope its kc,and not the heart murmour,how old is the puppy,my friend who has gordon setters,did have a king charles cavaliar weather she still has her i donot know but at the time she had a heart murmour my friend said it is known in the breed to have this problam,but all the best,