Why are Grapes Bad for Dogs?

Gage asks: Why are grapes bad for dogs?

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:

  1. Make them vomit (if they are affected by grapes, they probably will vomit anyways, but if not, make them).
  2. 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.
  3. 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

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  • This is not true in my experience. I have a vineyard and have worked in wineries and have seen dogs eating many grapes. The only effect I have seen is a lot of seed in poop

    • Just like the artical said, some dogs are not affected . Grapes are usually indigenous to that area and potentially so are the dogs you witnessed eating them. Any animal ( including us) are rarely allergic to foods grown that are indigenous to same area of their ancestors.

  • My dog every now and then eats a grape but it is only one and all he does is play with it and rarley eats it afterword, he has eaten one or two but only about one a week, nothing in the list above shown but it is never a bunch of grapes, only 1.

  • The article says 2 out of 3 dogs are not affected. Perhaps it’s just the more sensitive dogs that get sick or die. My friends husky ate a lunch size box of raisins and almost died. My cattle dog mix can eat pretty much anything.

  • We have just lost our wonderful Border Terrier, she had learnt how to open doors, and managed to open a kitchen cupboard door one afternoon, my daughter told me she had eaten the dried frut mix, but i just thought she would get an upset stomach. I was very wrong with in 12 hours she started to be sick and she died in the vets the following night. We did not do a post morton, as we were so upset and just wanted her to be buried as beatiful as she was. We now realise after researching on the internet it must have been the mixed fruit, the vet did an xray when we first took her in but could not see anything wrong. She had all the symptons that are described on all the sites regarding raisins. Please beware and learn from our mistake. We loved her so much and is a devasting loss to all the family.

    • Our Border Murph ate only two grapes and ten hours later he was puking red…the kids came down and said you’re not to feed dogs grapes so I learned my lesson. Sorry to hear about your loss, Borders are great dogs & friends.

  • Our 10 lb terrier gulped down a single red grape that fell on the floor. To be safe we called the vet who said yes this is a real issue and even for a single grape it’s best to be cautious and assume the worst. So to induce vomiting we were told to give her 1 tsp of hydrogen peroxide given her size, which she licked right off the spoon. 10 min later, yucky grape speckled vomit on the floor. Lesson learned, don’t drop grapes on the floor and have some peroxide around the house just in case,

  • My dogs eat grapes a lot and have for years
    they have had no reaction to them. They eat rasains also. Have 4 Boston Terriers

  • i have a cockapoo, and use to give him grapes here and there before i found out that it was bad. He seemed fine after eating them, but don’t give him any now.

  • I have a terrier mix and she loves grapes but now after reading about this im super scared. She has been eating grapes since I have had her from a baby and she is almost 2 now. But now I have to break her little heart.

    • I have been feeding my labrador grapes, cherries and raisons and blackberries which he loves, for the past 4 years and hes had no adverse reactions. He doesnt like any other fruits I have offered him though. He also ate a massive bar of dark chocolate about 5 years ago (accidently on my part) and her was perfectly fine. But I understand it may not be that way for every dog.

  • Before reading this article, I did believe that too many grapes might be bad for some dogs. Now I am undecided.

    My own fourteen year-old Australian Terrier has eaten grapes in abundance all his life – obviously among the ?majority? who are unaffected.

    A major flaw in this article is a lack of reference to the study on which it says it is based. An internet search for “Animal Poison Control Center” produces a group which eschews traditional research in favour of anecdotal studies. The only published information which I see there on grape toxicity finds that many dogs who died of kidney failure were known to have eaten a few grapes or raisins up to two weeks before. (I am sure the same would be true of most humans who died of kidney failure.) No potential link between grapes and kidney failure are provided, although some of the obvious ones seem to be ruled out. Actually, if my dog died unexpectedly (with all respect and condolences to Stephanie), I would suspect something he had eaten about which I did NOT know.

    This is definitely a topic which could benefit from some traditional research. What we have reported here seems little better than gossip. Also having a younger dog, which has not been exposed to grapes (to my knowledge), I would really like to know if grapes really are toxic to some dogs. More importantly, is there a non-lethal method to determine if a particular dog is at risk?

    Any veterinary students or professors out there in need of a project?

    • Daven Hiskey

      @Robert Morewood: References at the bottom, as always.

      • Thanks for the article, and very sorry to hear that some dogs have died.
        I am not sure about the references however. There are four. Three of them are secondhand sources which refer to an ASPCA study. The fourth is a dead link on the ASPCA website, presumably the study referred to by the other 3.
        It would be good to know of any other research, as grapes and raisins are often in easy reach of our dogs.

    • How many dogs are they allowed to kill? Should they feed the equivalent amount to every breed by gram per pound just to get the best results. I’m sure if you propose this idea to the ASPCA for a grant it will be quickly forthcoming.

  • My Yorkie loves grapes she plays with them and eats them. One day she ate about 10 grapes and they have never affected her, but I don’t like to take risks either. So I’m going to stop feeding her grapes after reading this! It seems like all the terrier breeds don’t have an issue I’m making this assumption based on the fact that a lot of people who commented stated that their dogs eat grapes all the time are of a terrier breed. I’m sorry to everyone who lost a dog behind this:(

    • Thank you for your post. My yorkie just did the same thing, and reading about the danger I was frantic until I found your post. He seems fine now, it’s been a few hours and I am calming down since I read your post.

  • I have a shipperkie dog for 9 yrs and she loves grapes she can eat a bag of grapes in two or three days by herself and she has done this like I said for 9 yrs. I quess like they say not all dogs go throught this thank God my did not effect her. thank you all for your info she will stop eating them .

  • My Pomeranian (actually Klein Spitz) who I got directly from Germany ate chocolate AND grapes and neither did anything to her. But flea medication meant for dogs had poisoned her and she almost died from it!

    • I had a schnauzer who would get on the couch, jump the aquarium, jump the bar and climb up to the cabinets and steal Hershey’s kisses. A lot. She lived to be ripe and old. I also had to hide the kisses. Lol she was so wonderful. I miss her so. I am very careful now with my fur kids.

  • I wonder if older dogs are more susceptible to grape poisoning. My daughter used to have a Black Lab who would often help himself to grapes growing in the yard when suddenly one day he became ill and died of kidney failure. The vet was not able to discover any other cause. I believe that as he aged his body lost it’s ability to tolerate the grapes and it killed him. If I owned a dog I loved I would NEVER give it or let it have access to grapes – EVER !!!

  • My wife was out shopping today and I got the munchies for some grapes. I decided to share 6 grapes with my newly adopted 10 month old beagle/dachshund. Something told me after she ate the grapes to call the veterinarian and ask if it’s ok to give grapes to a dog. I was told NO and they made an emergency appointment for the dog. They gave her activated charcoal and she vomited up 5 undigested grapes. She seems fine now but I have to bring her back tomorrow for blood work to be sure. From now on the puppy only gets DOG food, nothing else. Thank you St. Francis of Assisi!

  • i just feed my jackrussel about 4 grapes and are very worried after reading these I don’t know if I should just see what happens or contact the vet. my mom was on her phone I asked her if he could have some grapes too, she had no answer for me so I presumed with giving him 3 or 4 grapes once she had gotten off her phone and realized that I was feeding him grapes she told me that he could get very sick from eating them so I went on google to research what can happen to them and now uopn reading these I am quite worried of what might happen. my dog is about to be 9 soon and I read it can effect older dogs easier I don’t know if that is true but Im still scared, im hoping my dog will be one that doesn’t get affected by this, and I can now inform other people about this so maybe I can save an animal I couldn’t imagine how i’d feel if my dog got very sick or even past away because of me.

  • My 2 dogs are in the vet hospital right now, finishing up the 1st 24 hours of a planned 48-hours of IV fluids, and both had to have vomiting induced and charcoal given. My emergency vet was ABSOLUTELY ADAMANT that this can be a life-threatening emergency (they both ate grapes) and while you never know which dogs will be affected, this can and does cause acute kidney failure. Stop second-guessing the article and call a vet if you want to know. Call 20! I’m happy as heck that so many have have their pets eat these and be fine, but don’t for one second think the threat is not real. I am beside myself and have cried my heart out all day, and my babies are still not out of the woods. It’s horrible and heart-breaking and A REAL THREAT.

  • After countless hours of research on this subject, THERE IS NO DEFINITIVE PROOF THAT GRAPES ARE POISINESS TO DOGS! There have been no research and no studies AT ALL! It is an urban myth, and the APCC has done no studies! The closest to this actually MAY occurring is grapes from SA where they use a pesticide that has been banned here. I challenge anyone to show me ACTUAL PROOF that there are ACTUAL studies and scientific research that has been done. Just don’t give a dog ANY unwashed fruits or vegetables that could be suspect with pesticide. My dog has been eating grapes since a pup and is as healthy as any pet! The same with onions! COOKED onions. C’mon people, get that facts! The FACTS!!!, not internet hype and urban myths! If your dogs were poisoned, chances are very HIGH it wasn’t grapes!

    • If no studies have been done, how can you say that it’s an urban myth? Just because no study has been done to prove grapes are toxic to some dogs doesn’t mean they are not.

  • Shame on you,mate.
    This myth has been debunked by more than a few surveys of breeders and vets where ZERO dogs have ever been documented as having died from eating grapes.
    A lot of evidence for this phenomena points to the ASPCA buying the animal poison control center call center in 2009.
    Since that time the APCC has been scaring countless pet owners to the vet for expensive treatment at $60 a call.
    Your posts are usually more objective, but you didn’t exercise due diligence before passing on this dangerous information.
    If grapes were toxic everyone with a concord grape vine couldn’t own a dog, they would all drop dead.
    How many folks do you know in the country who have a Labrador and concord grapes on the same place?

    Don’t believe me, search for ANY peer reviewed research that supports the premise that grapes are toxic for dogs.
    I am confidant you will find nothing except dubious claims by folks with fiduciary interests in keeping this myth alive.

  • most grapes and raisins are treated with sulfites as a preservative (sulfur dioxide) I wonder if that has anything to do with it. It is the reason people get diarrhea when eating raisins

  • I was a military research toxicologist for 16 years, the for the last four of those I was the scientific director of the military’s largest environmental toxicology laboratory. I mention this only to support my qualifications to perform toxicology database research. I first learned about the alleged poisoning of dogs by grapes and raisins earlier today, so I decided to systematically perform a database research investigation of this alleged phenomenon. After spending a few hours looking through toxicology publication databases, Pubmed, and Google Scholar I could find no scientific study that addresses the issue. I find this odd, because I found several scientifically valid studies of grape extracts, that conclusively demonstrate no effect of the extracts on dogs’ health. Liver toxicity studies are among the easiest to run. because over 99% of all meaningful answers can be derived from simple blood chemistry analyses, alone. It seems odd to me, that if this phenomenon was a real one, nobody would have actually investigated it. One thing that causes me to conclude that this is a myth, not unrelated to the self accelerating Audis of the 1980s, ultimately demonstrated to be caused by human error and cognitive masking, is the purported “fact”, that it occurs ion only a subset of dogs, and is unrelated to breed. As part of my formal pharmacology and toxicology training, inter-species response to xenobiotic agents was emphasized, because such research is often intended for extrapolation of the results to humans (especially in pharmacology). While inter-species difference in responding to xenobiotics is very common, it is less so for members of the same species There are many different strains of Rattus norvegicus (lab rat) that look pretty much the same, but, most breeds of dogs look very different even though they are all the same species. In rat toxicology research it is not uncommon to find differences in response to xenobiotic compounds that are shared within a strain, however, all members of the strain share the strain’s response profile (and many times the rat strains are specifically bred to accentuate these differences). Breeds of dogs, are biologically equivalent to strains of rats, so if you were to document a differential drug response, it would most likely exist in, pretty much, the entire breed. That there doesn’t appear to be sufficient evidence to conclude that this sensitivity to grapes is specific to one breed, or related breeds, of dogs, suggests that the sensitivity isn’t a genetic trait (i.e., bred into the animal). Judging by the divergence of the affected groups, I would predict that, if this phenomenon is ever actually studied, it will be eventually described as a canine idiopathic toxicity (i.e., toxicity without any determined cause)..

  • When did dogs (and cats) suddenly developed allergies to EVERYTHING and supposedly die from eating human foods? I’m in my sixties and have owned at least 25 or more cats and dogs in my lifetime. I didn’t live in the country or backwoods. I lived in the city. Our dogs ate EVERYTHING.The cats were more finicky, but they did eat chicken, turkey, gravy and dairy scraps. Leftovers on our plates after meals were all scraped into a bowl and collected throughout the day and added to the dog’s food pan after dinner in the evening. With the exception of the occasional pet vs motor vehicle death, all of our animals lived to a ripe old age. The exceptions to this record were three cats that I was guilted into giving the myriad of recommended immunizations and convinced to put them on special prescription diets. One of those cats died before age 5 of lymphoma; one died at 11 of diabetes and his brother died at 5 from bladder crystals, which I believe resulted from the prescription dry cat food that was prescribed for him. In stark contrast, the cat that lived to be 23 years old never had immunizations or routine trips to the vet, except to be neutered as a kitten. He would fight a running buzz saw for a can of yogurt covered raisins. For the most part, all of my animals have been free of diseases previously attributed only to humans.

    The first clue that pharmaceutical companies might be manufacturing pseudo illnesses and perpetuating the myth that food such as chocolate and grapes will kill your dogs might be that you’re now able to get your pet’s meds at your own pharmacy. Have you ever been in your doctor’s office and seen a pharmaceutical rep bringing in a catered lunch for the doctor and his staff? They also bring free notepads, pens, samples of meds and cute little magnets and cup coozies. These are incentives for prescribing their company’s branded meds and now they’re selling their wares to your veterinarian.

    Does your vet sell things other than meds and prescription pet foods in their waiting room? For example, dog/cat collars, toys, scented candles to eliminate pet odors, etc? They’ve bought into the whole merchandising game now too. There’s also pet insurance and credit plans to help with the outrageous fees for services (one friend took her cat in the other day and ended up with over $3000 in charges for ‘tests’). You used to be able to help you dearly departed pet cross the Rainbow Bridge for $25. Now the injection is over $100 and there are ‘disposal’ choices, such as cremation and burial in exclusive pet cemeteries and customized headstones to consider. But who can blame the vets? Gone are the days when they could feed their own family simply by trading their services in exchange for a few of your chickens or your cow’s milk or first calf.

    ‘Waste not want not’ was a popular saying among Americans who had survived the Great Depression; but somewhere thereafter, things got weird. Young urban professionals had more disposable income and they stopped having babies and started dressing up their pets. I had a neighbor with a pair of Weimeraners who each got a Hershey bar after dinner but they lived to a ripe old age. I also had an aunt and uncle who had two shihtzus that loved to go thru the drive thru at Dairy Queen. They didn’t get diarrhea from eating dairy products and they lived a long and healthy life.

    Don’t get me wrong, I love my animals dearly; but I’m holistic in my approach to both my own healthcare and theirs. I don’t take meds unless it’s absolutely unavoidable and I don’t run them to the vet if I can treat them with something provided for free by Mother Nature. A tiny carton of plain yogurt is less than $1 and will usually settle an upset stomach. A few spoonfuls of pumpkin puree 3 times a day will cure most any lower intestinal issue. But should they develop an infection or need medication, then certainly, I don’t hesitate to consult a professional. I just don’t take them places where they are exposed to diseases and I don’t put poisons like flea & tick killer and other preparations that contain a form of arsenic into their systems.

    I think perhaps the merchandising of veterinary care and the animal’s precarious intestinal fortitude and fragility of health might have started when the first GMO puppy was dressed in a tutu and stuffed into a Louis Vuitton carrier. Get back to basics. Stop treating animals like dolls or human infants and perhaps they’ll regain their strength and dignity, so that a grape doesn’t mean certain death.

  • even our children are sensitive to things like gluten. i have grapes and a dog that loves grapes i try to keep them from her but seems impossible she has had no symptoms she is young and part australian sheppard and blue heeled. i didn’t know till rescently. must be resistant. also we grow with no pesticides only diatomaceous earth now and again. so glad she never got sick

  • My Dalmation Lurcher cross ate grapes all her life, but only seedless white grapes, she was the epitome of health and fitness. She liked to catch them when thrown, and that can get through a lot of grapes. Never the slightest effect. I think white grapes are OK, but red not since they contain substantial amounts of tannins and other chemicals in the skin, lacking in white grapes.