It's not exclusive to puppies! Ozzie has ALWAYS done this. We call it "wildman mode" and know to steer clear and try to keep things out of his way so he doesn't get hurt. (Like shoes or the groceries I just brought in.)
He runs with a toy usually and sometimes will take short breaks during which he shakes like crazy then tosses and often catches the toy. Then running resumes. At some point, he will usually bring the toy to us, signaling the end of the mode and that he now wants us to get involved. On occasion, if he looks completely out of breath, I'll slow him and then make him stop. Now that he's getting older, I pay lots more attention to that heavy-breathing! |