Have you seen a dog in a gas chamber? They whine and wrestle around before scumbing. Not sure its because they suspect something is wrong, or they are feeling the effects of gas, but there is at least some mental anguish. My grandfather used to slaughter a hog every few years, one .22 shot between the eyes and the animal drops without a grunt. Pretty sure its just like when you pass out, the world just gets instantly dark.
No, I have never seen a dog in a gas chamber. What humane agency that you know of still employs this? (Re: your post #118)