When dealing with seriously ill dogs (dogs with heart and kidney failure), we often hear this sentence: "He is a good puppy, he can hold on." Behind this statement lies a cruel yet intricate biological logic— metabolic balance . This is a vital mechanism issue that both humans and animals must confront: Iatrogenic injury > ATP repair speed = System failure Because the core iron law of cell biology is: without energy (ATP), there is no repair. If we consider the body as a