The last rancher I worked for would not kill the sick or injured stock he had. He called the thing a dead bolt because it drives a shaft deep into the brain. His hands were steady and sure as he put it against their foreheads and snapped the trigger. I only saw him cry once, when a strawberry filly sawed her leg off in the barbed wire. I went off and done some more crying myself.
Horses are different.
It was almost as hard as being asked to put Marleen down. I begged a special prayer of the Lord, and let her go. The old dead-bolt that took the filly down brought her low. I kept my eyes closed and begged for forgiveness. Then I covered her up forever.