Ok, interesting. The Mcmurray link you posted actually provided a name for the alleged mystery toxin: Persin. However, they also say that it is found specifically in the skin and the pit of the avocado--not, apparently, the flesh. Wikipedia says this about Persin:
"In birds (which are particularly sensitive to the avocado toxin), the symptoms are: increased heart rate, myocardial tissue damage, labored breathing, disordered plumage, unrest, weakness, and apathy. High doses cause acute respiratory syndrome (
asphyxia), with death approximately 12 to 24 hours after consumption."
So the issue is not the flesh, only the skin and the pit. Which I have never seen a chicken eat, anyway! Very informative.
Nice to finally get the clear answer I've been looking for!
Cheers, Courtney!