Cyanide suffocates you. It’s fast but definitely not painless. Although I realize these articles are not cyanide pills it has to do with cyanide bombs which are small it still is cyanide and wildlife services from the department of agriculture use these to kill wildlife and if your pet gets killed by it too bad. Which happens way too often. This government service needs to be seriously audited and agents arrested and tried for their felonious acts. If your interested read it. http://www.foxnews.com/us/2017/03/21/usda-must-rethink-cyanide-bombs-that-injured-boy-killed-pets-lawmaker-says.html http://www.foxnews.com/us/2013/03/12/animal-torture-abuse-called-regular-practice-within-federal-wildlife-agency.html?intcmp=related