If you've wondered about grapes for dogs before, here's a good article. Please do not be dissuaded by people who claim "oh my dog eats grapes ,chocolate and never had a problem.". http://www.aspcapro.org/mydocuments/grapes.pdf
I think grapes are one of those things you should just avoid period. Yes, some dogs can eat them and get away with it - given everything that can be toxic to dogs, there are usually some dogs out there that can get away with eating each one. My Cey got into some avocado once that we had saved for our pet rat, right after we first got him (Cey, not the rat lol). I knew avocado was on the no-no list and I sort of freaked out - but he was fine. Will I ever let him eat avocado again, knowingly? Of course not - there are waaaaayyy too many other healthy and good treats out there for him!
Also, does anybody *really* let their dog eat chocolate? I know a puppy that died after getting into a bag of chocolate chips, so I know first hand how toxic chocolate can be... grapes seem a little less dangerous in general
for most dogs, but you just never know...