Eating a significant quantity of grapes (32 g of grapes per kg of dog) can potentially be fatal to dogs, though not to all dogs. About 2/3 of dogs are unaffected by grapes according to a study done by the Animal Poison Control Center. Dried grapes (a.k.a. raisins) seem to be just as fatal as their fresher counterparts to those dogs that are affected.
As to why grapes and raisins are bad for some dogs, generically speaking it’s because grapes and raisins can cause rapid renal failure (kidney failure). The exact mechanism behind the kidney failure after consumption of grapes or raisins isn’t known. Potential agents spelling the canine’s kidney’s kismet, such as common pesticides used when growing grapes or various fungi, have been ruled out.
It doesn’t matter whether the grapes were grown in your own garden or were commercially grown, nor whether they are seeded or seedless (grape seed extract actually seems to be perfectly safe for all dogs). So something inherent to the grape itself, and apparently to all types of grapes, seems to be the culprit, but beyond that, nobody knows (yet).
If your dog does ingest more than a few grapes or raisins and they are among those affected by grapes, sometimes they can be saved. Once you discover your dog has eaten several grapes or raisins, you should immediately:
- Make them vomit (if they are affected by grapes, they probably will vomit anyways, but if not, make them).
- If you have it on hand, make them eat activated charcoal. This will decrease the absorption of whatever is causing the kidney failure. If you don’t have any activated charcoal handy, burn some toast (the blacker and more charred the better), then make them eat it. Normally getting dogs to eat things is amazingly easy, but you might find it significantly more difficult in this case, as dogs that are affected tend not to want to eat anything.
- Take them to a veterinarian. Aggressive introduction of intravenous fluids for about 48 hours has been shown to drastically increase the odds of your dog surviving. The quicker treatment begins, the more likely they’ll survive it, so don’t wait around for your dog to show symptoms. Plus, in the cases where the dog isn’t likely to survive, the dog can be euthanized on the spot without having to suffer a slow and painful death from kidney failure.
In case you’re curious about what the symptoms are that your dog might exhibit after eating a bunch of grapes, these include: vomiting, diarrhea, abdominal pain, loss of appetite, shaking, lethargy, decreased frequency of urination (and/or reduced volume of urine produced), and hypovolemia (decrease in blood plasma; get out your blood plasma testing kits kids!)
One of the other major things dogs are allergic too is chocolate; go here to find out why: Why Dogs are Allergic to Chocolate
Expand for References