Absolutely not. All parts of the oak tree are poisonous to guinea pigs. You can give them apple or pear branches if you want to give natural wood branches. Also make sure you don't give branches from fruits with pits, i.e. plums, peaches, and nectarines.
I'm really not sure fairysari. To be on the safe side, I'd say avoid them until one of the other mods who is more familiar with safe/dangerous plants can answer your question.
I spent a few hours the other night searching the net to see if they were safe, and couldn't find anything. I don't think the information is available online anywhere!
It's also called Shadbush iof that helps at all.
I live in an apartment, so I don't really have access to tree branches, but I was thinking of asking my parents if I could steal some branches from the trees in their yard. They don't use pesticides, so I know they'll be safe in that regard. I guess I'll have to find out what other trees they have.
Thanks, Percy's Mom. Luckily, we have an apple tree. Are fresh branches OK? I was thinking of keeping a branch about a foot long and 2-3 inch in diameter in the cage for chewing. Any problems with that?
Fresh apple branches are fine. I'd go with smaller diameter branches in shorter lengths though. A lot of pigs just ignore them anyway, 2-3" won't fit in their mouths to chew on, and something that long would just get tripped over in the cage. About 4" long is plenty long enough.
Thanks for the link, PiggieMom. But I don't think he ships to Canada.
I asked my mom about the other trees in the yard, but I can't remember what she told me there are. I'm going to start asking some friends who have yards if any of them have apple trees.