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Grapes and Raisins: Toxic or Not?

3490 Views 11 Replies 6 Participants Last post by  Pai
The Dog Press did a little research on the details of why raisins and grapes are listed as 'toxic to dogs', and came up with some interesting results:
Noticeably missing from any “toxic grape and raisin” report we found is any sort of reference to the likelihood of (ii) Pesticide Poisoning. On the contrary, the APCC site displays a puzzling letter from a veterinary toxicologist. It states in part, “Why did the fruit cause the dogs to become ill? No one knows. Suspect grapes and raisins have been screened for various pesticides, heavy metals (such as zinc or lead), and mycotoxins (fungal contaminants) and so far, all results have come back negative.”

When an APCC vet states that grapes caused the dog to become ill even though "no one knows" why, it is confusing at best. If “animal poison control” doesn’t know why or how grapes are poisonous to dogs, the SPCA should sponsor a study to find out! Even more worrisome, the next sentence directly contradicts the flood of warnings from NIH (National Institute of Health), FDA (Food and Drug Administration) and medical universities which stress washing all fruits and vegetables due to high pesticide contamination.

The Environmental Working Group (EWG), a non-profit research and advocacy group, issued a 2007 report in which the pesticide toxicity of fruits and vegetables was ranked according to FDA data. Imported grapes were the 10th worst with domestic grapes ranking 21st on the list of 43,000 samples! In addition to that compelling evidence, National Pet Press published a universally accepted list of pesticide contaminated produce and in 2008 The Dog Place published Produce Pesticides. (ref 6)

Therefore, when the ASPCA APCC states that no traces of pesticides could be found on grapes, it stretches logic (and Animal Poison Control Center credibility) to the breaking point. In fact, it is reminiscent of the (ii) 20/20 Report in which John Stossel asserted that neither organic nor conventional produce samples contained any pesticide residue…

A reasonable person would assume that dogs suffering from classic symptoms of chemical poisoning were poisoned by the chemicals sprayed on the fruit rather than the fruit itself.

Given that no component of the grape has ever been identified as toxic to dogs, (tannins have been eliminated) it could be grievously misleading to blame renal failure on grapes rather than toxic sprays, pesticides, or Lethal Chemicals (ref 7) used to ripen fruit.
I think the theory that it's some kind of 'ripening chemical' instead of the fruit itself is a compelling theory. Also, I know many people who used to give their dogs grapes for years before the fruits were added to the 'toxic to dogs' list, and never had anything bad happen. It IS strange, to say the least.

Has anyone here ever had a dog experience renal failure from eating grapes or raisins?
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We use to have a grape harbor around our patio fence.......my 8 year old Golden Retriever had ate grapes every year ( I noticed her ears always were worse after that so I tried to control her eating them much). At 8 years old she ate a bunch and got sick in the night....we rushed her to the vet the next morning and she died within a few minutes after arriving. I do think her age had something to do with it.....her body just could not tolerate grapes at that age. There may have been other things that caused it that I was not aware of......that's when I read that grapes could be problem. I cut down the grapes as I have two goldens now......never going to take that chance again.
Interesting article. I'm sure that pesticides have something to do with it but from what I've read, grapes aren't toxic to all dogs. Some dogs don't have a particular enzyme required to digest them so why take the chance and just not feed them? I can't remember where I read this but it was when I got my dog. I just wouldn't take any risk. And if pesticides were the real culprit, then we shouldn't feed any fruit, vegetables or animal unless they're certified 100% organic.
And if pesticides were the real culprit, then we shouldn't feed any fruit, vegetables or animal unless they're certified 100% organic.
You're already not supposed to eat any fruits or vegetables without thoroughly washing them for exactly that reason. They wouldn't tell people to do that if it wasn't a real health risk.

The fact that it seems there isn't any study into grape toxicity or any of the causes for it is pretty shocking, to me. Nobody seems to actually know why it happens at all, and you'd think the group responsible for announcing grapes can kill dogs would actually have some data about it. That's the part that makes me wonder the most. It's like there's holes in the information that they didn't fill in before announcing that grapes are dangerous. Do you have any links to research on the enzyme thing, or is that just a theory? I'm curious to know more about that, since the DogPress article says there are no studies that explain the link between grapes and renal failure. Kidney failure could be caused by chemical poisoning as well. Since no compounds in grapes have been proven to be toxic to dogs, the fact that some dogs are dying after eating them while many do not, and there's no hard scientific facts about why, is just plain strange.

I cut down the grapes as I have two goldens now......never going to take that chance again.
Perhaps they were old grapes and the fermentation had something to do with it? Did she die of renal failure (which is what grapes are accused of causing) or something else?
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Two weeks ago, my friend's 1.5 year old Newfie snatched a handful of grapes off of a cheese plate when she wasn't looking. She noticed right after and brought him to the E-vet, they kept him for the weekend so they could monitor him and told her that they don't know exactly what the level of toxicity is but that renal failure was a distinct possibility. Very scary but luckily Charlie is fine.
Yes, but see they don't know why or how it's caused. They just accept the explanation that grapes themselves are dangerous, even though no substance in grapes has tested as positive for toxicity to dogs. That's what confuses me -- either it's an individual dog problem (genetic issue) or there is some unknown factor in grapes that can kill some dogs but not others. Does it depend on the breed of grape? Is there something used to preserve or ripen grapes or raisins that is the culprit? Why is there no research into finding out any of that information?

If we found out the exact causes, we could develop an antidote. Not knowing anything other than the fact that 'some dogs who ate grapes died of renal failure' doesn't actually help anything.

I hate not having facts or research available about this. It really bugs me. Call me paranoid, but after the melamine dog food fiasco, I'm highly suspicious of 'renal failure' happening in dogs without a known reason and no investigation being done about it.
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Here is Part 2 of Dog Press' grape toxicity investigation.
People were surprised in France when I told them that grapes are poisonous to dogs. Lots of people had dogs eating grapes as they picked them and they have never been sick because of it.

I rather err on the side of caution but I would think that it's not poisonous.
A lot of substances used in U.S. produce are illegal in europe, I believe. I would be really interested in reading any surveys of dogs dying after eating grapes recorded in the EU, and knowing if that happens there at all or if it only seems to happen in the states.

Of course, it seems like no pet health organizations seem to care enough to actually research the topic before they make statements telling people that grapes are poisonous.
The reason that worries me, is that if it really IS a case of chemical poisoning from substances used to treat grape crops, it could be a danger to HUMANS (babies for example) as well. That's the main reason it should be further investigated, in my view. Questions like 'do other fruits use the same chemicals?' would be vital to ask, as that could me OTHER fruits could be potentially harmful for dogs to eat as well if it turns out that some dogs have a special sensitivity to a certain pesticide or ripening agent.
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I had read that the grape's skin had elements that were hard to process in the liver, and thus caused liver damage.
There are no actual studies that say anything like that. That's what is so mysterious about the whole thing. There are 'theories' everywhere but no facts.

As the article explains, whenever 'grape poison' cases are diagnosed, the ONLY source used for calling grapes as poisonous comes from the ONE organization's conclusion:
All either cited the APCC database as the basis for diagnosis or as in this report from the CABI Abstract, stated that the pathogenesis (origin) and nephrotoxicity (poisonous effect) was unknown, i.e. “This is the first report of clinical signs, treatment, and clinical outcome in dogs that developed renal failure after ingestion of raisins or grapes. The pathogenesis of nephrotoxicity associated with raisins and grapes remains unknown.
In other words, because one group made a statement that grapes are poisonous based on circumstantial cases where some dogs died after having eaten grapes (even though many dogs eat grapes and don't suffer any ill effects), everyone else just repeats what they said, there isn't any independent investigation into their conclusion that grapes are poisonous. It's all coming from one source that has not been researched, questioned, or cross checked. What other factors did those dogs share besides having eaten an unknown amount of grapes sometime before they experienced renal shutdown? Nobody knows. Nobody knows what the actual 'dosage' for toxicity is, or if there even IS one.

The Merck Veterinary Manual even admits that chemical poisoning is a possibility:
“Diagnosis [of grape poisoning] is based on history of exposure, along with clinical signs. Other causes of renal failure (eg, ethylene glycol, cholecalciferol) should be considered in the differential diagnosis.”
In other words, grape poisoning is apparently identical to chemical poisoning. Coincidence? If a dog dies of renal failure, and the owner admits they might have or did have a grape or three, then grapes get blamed and the case is closed. That's very unscientific.

Lots of people used to feed their dogs grapes before this statement that they were poisonous was released. Very few ever died from it, or else grape toxicity to dogs would have always been known. Would it be hard to believe that the fact that dogs who had eaten grapes might have also ingested something else, and that 'eating grapes' could have been a coincidence that was picked as a cause over something else? Who knows, because there isn't any research!
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Old dead threads should generally be left dead.

EDIT: Oh, I see now you're just spamming advertisement links to that site on every post you've made. Nevermind, then.
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