Liver failure may be
linked to grapes and raisins
The ASPCA Animal Poison Control Center is looking into a possible connection between kidney failure in canines and the digestion of grapes or raisins.  (they did a database search relating specifics foods to clinical cases across the country)

The estimated amount eaten ranged from 9 ounces (raisins) to 2 lbs (grapes).  The grapes came from grocery stores, vines in private yards, or fermented grapes from wineries, while the raisins involved were mostly commercial sun-dried raisins of various brands. Vomiting was reported in all of the dogs, anorexia, lethargy, and signs of abdominal pain were also reported.  After aggressive treatment, including I.V.fluids and medications, about half of the dogs recovered while the others died or had to be euthanized.

Because the exact role of grapes or raisins in these cases is still unclear, Jill Richardson, DVM said the APCC is working on a collaborative study with Colorado State University's College of Veterinary Medicine in an attempt to determine how the fruit contributed to these dogs' sickness or death. When asked if any amount of raisins or grapes would be safe for a dog to consume, Richardson said, "I don't know if there is a safe amount, but until we can find out, I wouldn't recommend gving dogs ANY raisins or grapes".