In my day it was never done, and the fights I have attended either in the dressing room or before dressing out, I have never witnessed a breatherlizer test....never even gave it a thought as to if they did it or not. Any fighter who would consume alcohol to the point of intoxication is either a bum fighter or nuts.
For the sake of argument, who would be qualified to give such a test, and if the fighter was say a .8, who would have the final word in saying the fight was off?
Interesting question, but I can't say with any authority that is is done.