When your dog or cat or horse coughs up mucous; this means they
have been "hyperventilating; hyperventilating is during hot weather
the animal "breathes with the tongue hanging out...what happens is:
when your dog "hyperventilates...mucous begins to collect @ the
back of the dog's throat; so your dog "coughs up this mucous;
if your dog or cat cannot cough up the mucus; then open the
dog's mouth and scrape the mucous out of the dog's mouth with your
fingers; then wash your hands...