When Cooper is relaxing, usually after he's had a good play in the backyard, he starts to breath heavily, kind of like he's got snot in his nose. That's what it sounds like, anyway. He exhales very deeply and makes these strange snorting noses in his throat. He does it all the time now, he seems fine but I wonder if he's actually sick, or has some form of doggy asthma? Anyone know what might be wrong?