I asked Mordy about avocados awhile back, since Kharma has an absolute passion for them. She told me the flesh was okay; it's the skin and pits that are toxic.
There might be trace amounts of the persin in the flesh - not enough to affect a dog as large as Kharma, that would be a problem for a small dog, but we didn't discuss that, I only asked her about Kharma.