Once, In a pet hospital, I was a veterinarian. So one day,a man with his wife came to the hospital rushing, seems like their puppy was injured and we had to take a look at him. The puppy was so cute and funny too as he wagged his tail and showed his funny face.He was injured at the leg. It was quite serious injury.
But It was running like it was perfectly alright. But after a moment, he just fell down. He did seriously strained himself too much and he's out of energy to move. His heart beat was going very fast, like 280 beats a minute. It was the fastest beat I ever know. And he was loosing to much of energy. He can't possibly breathe well. He was loosing a lot energy.He can possibly die by losing breath.
But we tried our best to make him breath and gave him an oxygen mask for him to breath.He was perfectly alright after that. After giving him the oxygen mask,he was able to breathe well.He jumped of the bed and the owner of the puppy was so happy to see him alive and alright...