I have not seen them on any of the posionous plant lists, we had a huge oak tree in Fla and I know my labs ate some of the acorns and never had a problem but they didnt make a meal of them daily, just the occassional snack :wink:
Dex was in love with acorns when he was that age. We tried to discourage him, but he just lost interest after awhile. I don't think it's the best for them to eat them, but I think as long as it's not in large quantities it's not terrible either.
You may want to be careful about the acorns. They contain tannic acid which is poisonous and can cause vomiting, diarhhea, etc. I think these symptoms occur when large quantities of acorns are ingested, but you might want to discourage Wrigley from eating them anyway.
Easier said than done though, I know! Half of our yard is covered in wood chips and Boo used to eat them like they were going out of style. :x Drove me nuts, I had to watch him like a hawk, and was always yelling "No eat!" :?