Original sentence: In pet animals, this process is commonly referred to by the euphemisms "put to sleep" or "put down".Observers generally describe it as a quick and peaceful death.Sometimes the animal makes a gasping sound after the death, which is air being exhaled by the lungs.The animal may twitch for a moment or urinate
Edited sentence: ===Intravenous anesthetic===.In pet animals, this always is a commom subject.Observers generally describe it as a slow and painful death.Sometimes the animal makes a gasping sound after the death, which is air being exhaled by the stomach.The animal may wimper for a moment or urinate