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Are Grapes Toxic for Dogs?

Grapes may seem harmless on sight, but you'd be surprised at how bad they can be for a four-legger. Veterinarian Eric Barchas gives us the skinny.

 |  Mar 26th 2013  |   7 Contributions


When I was a child, my father told me that grapes were a superfood. The term superfood hadn't been invented at the time, and thankfully nobody in America had ever heard of the acai berry, but the word describes my father's meaning perfectly.

Grapes, he advised me, had a good balance of vitamins and minerals and sugars. If I were to ever find myself stranded on a desert island with only one food, I should hope that the food would be grapes (especially since they contain plenty of water). My dad did not go into the details of how one might request a supply of grapes on a desert island, but worries about such trivialities did not enter my young mind.

A couple of decades later, in vet school, grapes were still considered to be awesome. They made great snacks for vet students during study sessions. They also were touted by everyone I knew as relatively healthy (although potentially fattening) treats for dogs.

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They seem harmless, but they might not be. Fresh grapes by Shutterstock.

My cohort and I graduated from veterinary school into a world where vets routinely recommended grapes as treats for dogs.

Oops.

A couple of years after I graduated from vet school, a startling discovery was made: Grapes had the potential to be toxic to dogs. The toxicity, when it occurred, was serious. Kidney failure and death could occur. The identity of the toxin was unknown.

So there you have it. Grapes are toxic to dogs. No dog should ever be fed even a single grape or raisin. Dogs who have consumed grapes or raisins should be treated immediately by a veterinarian. The standard treatment is decontamination (vomiting, if the grapes were eaten within the last few hours) followed by 48 hours of hospitalization for IV fluids with regular kidney testing before, during, and after treatment.

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"The grapes are for me. I brought kibble for you." Woman having a picnic with her dog by Shutterstock.

I once consulted with a veterinary toxicologist about a 90-pound Pit Bull who had eaten two raisins. The dog was brought to my office in less than an hour, and my staff and I caused the dog to vomit. Both raisins came up. The toxicologist recommended two days of hospitalization for IV fluids with regular kidney testing before, during, and after treatment. I was incredulous. I emphasized the dog's size, the low level of exposure, and the rapid and completely successful decontamination. The toxicologist stood by her recommendation. I remember her words. She said, "There is no safe dose of grapes or raisins. All cases should be treated." As an aside, my house has been grape- and raisin-free since that night.

So there is the bad news. But let's keep things in perspective. Remember all those dogs from my early career who were given grapes with my blessing? None of them ever experienced toxicity. How is this possible?

Grape toxicity is mysterious and very poorly understood. But a few things seem clear. Not all grapes are toxic. In fact, most experts don't believe that grapes themselves are toxic at all. They think it's more likely that a fungus, which may or may not be growing on the grapes in your kitchen, is the culprit. Furthermore, not all dogs appear to be sensitive to the toxin. But those that are will be in big trouble if they eat the wrong grapes.

In other words, some dogs can get away with eating some grapes some of the time. In fact, most dogs probably can get away with eating most grapes most of the time. Therefore, some owners are inclined not to treat dogs who have consumed grapes.

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Grapes and raisins are toxic to dogs, so know what you're giving your canine companion. Feed the dog by Shutterstock.

That attitude, in my opinion, is a bit like playing Russian roulette -- only you're gambling with your dog's life, rather than your own (which is hardly fair to your dog).

I therefore follow the toxicologist's recommendation, and I encourage all owners of grape-eating dogs to seek immediate veterinary care and to follow through with hospitalization, fluids, and testing.

But my strongest recommendation of all is to practice prevention. There are no grapes or raisins in my house, and that helps my pal Buster stay safe (along with my wallet -- hospitalization, fluids, and testing add up quickly, even for a vet). But I must say that I enjoy gorging on my childhood superfood whenever I'm out without him.

More articles on digestive issues and poisons:

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(Note that if you have an emergency situation, please see your own vet immediately!)

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