'Trust Me, I'm a Vet'....

[Mudmagnets]

This is what I found by Googling - not sure how many the dog would need to be affected though, how many is a small amount I don't feed my dogs human food...for the simple reason all 3  would like some of what I've got and I would not get any peace at meal or snack times, so the rules are 'It's mine - go lie down'

Grapes and Raisins
What could seem more harmless than grapes? They're a perfect natural snack for children, and some dogs love them. Yet even small amounts can cause lethargy, depression, and kidney failure. Vomiting and hyperactivity are early signs of grape poisoning.
CREDIT: istockphoto

[Archie bean]

The difficulty with grapes and raisins is that it would seem that not all dogs have a problem with them. They are extremely poisonous to some dogs but harmless to others.....no one knows why. Safest option is to avoid them.

http://www.petful.com/pet-health/how-toxic-are-grapes-for-dogs/

[piph]

Thanks for that - I wasn't quite sure why they were bad for dogs.

[Pearly]

The difficulty with grapes and raisins is that it would seem that not all dogs have a problem with them. They are extremely poisonous to some dogs but harmless to others.....no one knows why. Safest option is to avoid them.

http://www.petful.com/pet-health/how-toxic-are-grapes-for-dogs/

and it costs £192 out of hours if your dog does eat a grape (or 3!). We were advised she may be ok but there were no guarantees hence taking her to the Vets.

My first dog loved grapes.  He liked them sliced in half and would lie, nibbling the flesh off the skins, for hours if allowed.  He never ate the skins which always amused us at the time (30 years ago) now it intrigues me.  He was a big lad, GSD x Labrador - those grapes were tiny in comparison!