Toxicology Tuesday, July 10

Fruits and vegetables are good for you – aren’t they? What’s your response to the now-familiar refrain,

Toxic or Not?

Answer: This one may surprise you – grapes and raisins are not only toxic to dogs, they could be life-threatening. This is a relatively new problem in veterinary medicine. It wasn’t until July 2004 that the ASPCA Animal Poison Control Center released a nationwide alert about the potential toxicity of grapes and raisins, after 10 canine poisoning cases were reported between 1999 and 2001. These cases included ingestion of both red and white grapes, fermented grapes from wineries, and various brands of commercial sun-dried raisins.

We still don’t know the toxic mechanism of action, nor even what amount of grapes or raisins it takes to cause poisoning. Since 4 lbs of grapes equals 1 lb of raisins, it is presumed that it would take a smaller amount of raisins to reach the toxic threshold. To date, there have been no other reports of poisoning in other species from grapes or raisins.

Clinical signs include acute GI signs (anorexia, vomiting, diarrhea, abdominal pain) within the first few hours of ingestion, which may last days or weeks. In some cases, acute renal (kidney) failure develops, usually within the first 3 days. If the acute phase of kidney failure is not treated early or aggressively enough, or if the initial insult to the kidneys was too severe, it might even be fatal.