The vet gives them a sedative first. It acts really really fast. You can see them act a little confused at first, wondering why they can't keep their eyes open. Then they go limp. Bento droooled a bit on the floor. Tigtig's eyes didn't close all the way. Once they are knocked out, the last drug is administered into the bloodstream through a catheter. It slowly stops their heart. Bento died within a minute or two. Tigtig's veins were really small, so they administered it directly to her kidney. It took a few minutes. The vet keeps a stethoscope above the heart, listening as it slows to a stop. Their lungs stop. They stop.