Thanks, Lynnie, for inspiring me to research this issue. But, wow, can’t find anything by way of real science on it. No scientific papers about the chemistry, teh supposed toxicity, or how it affects dogs or any other animal, which is just plain odd. (By contrast, there’s plenty of solid info out there on teh effects of chocolate.)
Lots of passed-along warnings on websites and chat boards. But no hard facts.
It just doesn’t add up.
Will research further by phone in coming weeks.
Meanwhile, teh full story is over in teh Forum; link at bottom of page here (forget how these work, you may have to do a little hunting in the “Sally’s Column” section to find teh topic).
Anybody know anything, with supporting links/references? I’m baffled.
P.S. Here’s my old dog Duke, who lived a long and happy life, to age 17, very old for a dog of his size (80 lbs). He ate raisin bread & bagels often. And he loved onions or garlic in anything.

Here’s a website run by vets, breeders, and other dog professionals, who are thinking along the same lines as me on this grape thing. Search for “grapes,” or just start with this:
http://www.thedogplace.org/Nutrition/Grapes-Poison-Dogs-09061.asp