My GSP has had this foam/drool at the mouth when she is excited or excercised since about 7 or 8 months old. Just sitting around she is okay but the minutes we are ready to do something and she is excited, the foam starts. 10-15 minutes into our walk she has more foam and is drooling on both side of her mouth and my vet says there isn't anything he can do. She wasn't always like this and we feed her Iams Puppy up until last month where we switched to Proplain Performance. What do you guys suggest?
Thanks.