The eyes of different breeds of dogs have different shapes, dimensions, and retina configurations.  Many long-nosed breeds have a "visual streak"—a wide foveal region that runs across the width of the retina and gives them a very wide field of excellent vision. Some long-muzzled breeds, in particular, the sighthounds , have a field of vision up to 270° (compared to 180° for humans). Short-nosed breeds, on the other hand, have an "area centralis": a central patch with up to three times the density of nerve endings as the visual streak, giving them detailed sight much more like a human's. Some broad-headed breeds with short noses have a field of vision similar to that of humans.  
My dog Sam is just over 4 months old (growing so fast!!) and is a yellow lab. He does normal puppy things like run around and is extremely energetic, but lately I have been noticing he has been panting…especially today. He walks around the house with his mouse open like he just went for a run with us but he hasn’t. The past few days he has had this sort of wheezing sound, almost like a cat would do if it had a hairball. He does this randomly then goes back to his normal self. Is this any reason for concern? Would love some input, thanks!