Dear Doctor: Not Even One Raisin?


Q. I know you’re not supposed to feed your dog any grapes, raisins, onions, or garlic, but is it really true that even one raisin or grape is poisonous? Or one slice of onion or a bit of garlic? I mean, after all, while they say not to feed your dog chocolate, I know anecdotally that a tiny piece of chocolate is not going hurt most dogs.

Carl Hiller

Canton, Ohio

Dear Mr. Hiller,

A. Let’s start with the fruit. Your suspicion that just one raisin or grape will not kill a dog is correct. Even a little dog can get away with it. But why court danger? A small amount of either fruit (raisins are dried grapes) can prove deadly by leading to sudden kidney failure and the inability to produce urine. That causes toxins to build up in the blood and make their way to every tissue in the body.

The exact mechanism by which the toxicity occurs is not well understood, but vomiting and diarrhea can begin within a few hours of eating these fruits. Other symptoms include weakness and abdominal pain. Death can ensue within just days. It’s for that reason that veterinarians suggest not getting your dog used to the taste of raisins or grapes by offering them one or two here and there when you’re taking some for yourself. There’s just too little room for error.

Interestingly, not all dogs are affected. But do you really want to find out if yours is one of them?

When it comes to onions and garlic — and chives, by the way — any amount is a bad idea. These foods can cause a form of something called hemolytic anemia, an illness that leads red blood cells to die prematurely. Without enough red blood cells, oxygen cannot get to all the body’s tissues, and the dog can become cyanotic. In this case, the effect can be cumulative. In other words, it’s not about how many onion slices your dog eats in one sitting. The damage can occur with a build-up.

The onions don’t have to be raw to do harm. Onion rings, the dehydrated onions in prepared soups, onions sauted with mushrooms or hidden with garlic in spaghetti sauce — all of these can make a dog sick. Think twice before handing your dog a tiny piece of pizza or a plate with leftover sauce from pasta, no matter how much she loves it.


  1. My mother used to give her chihuahua garlic pills daily from about 1 year old.
    Someone told her it was a natural remedy for fleas. The dog lived to be 15 years old.

    • It’s a chihuahua, that’s how long they’re typically supposed to last anyway. I’m sure the pills did not help, at least with its lifespan, more than anything it’s a waste of money.

    • Yeah, I’ve heard that myth about garlic repelling fleas, but I never gave my dog any, thankfully. I had a black lab who lived to be 15. She and I routinely ate grapes in the evenings. I guess I was lucky that she was one of those dogs who didn’t get sick from eating them. I always check to make sure a food is safe for dogs now before giving my dog any. I have a small dog now and little dogs only have to eat a small amount of something bad to get sick.

  2. My maltese, 4 years old, ate a raisin. 24 hours later, he is still fine, with no diarrhea or vomiting, and has a healthy appetite and is active. Does he need treatment? I am unable to go to an animal hospital.

  3. Hey ,I hope that your dog is ok ??? sorry just one quick question , did it affect your dog in any way ??? Did you end up taking him to the vet ??

  4. More fear mongering crap from sites that are either trying to be sensationalistic to get hits, or support veterinarians who don’t mind feeding the public BS so they can get some extra $$$$ out of people who don’t know better.

    Unless your dog is extremely sensitive to raisins/grapes in the same way a person may be allergic to peanuts, a grape or a raisin is not going to harm them; neither will a tiny bit of garlic now and again.

    I wouldn’t recommend people give their pets these foods because they aren’t good for them, but if you did and are reading this don’t panic.

  5. Raisins and Grapes are dangerous and I would never chance it. However the one thing that is ok and even good for our dogs apart fro. 1 or 2 particular breeds is Garlic!
    The study done previously was very flawed and even the guy who done it back tracked but the word was already out. It would actually take a very large amount of cloves of garlic per day to be a problem. A little bit is good for dogs.

  6. DogDad I completely agree! There is zero oversite in the veterinary world. After having watched a show, Market Place up here in Canada, it was found that even the amount of vaccines that the vets say are necessary is grossly exaggerated. That dogs are like people after the initial puppy vaccines, most pooches ONLY REQUIRE BOOSTER SHOTS EVERY 4 TO 8 YEARS depending on size, the rate at which they age and living environments. Also most meds that vets prescribed can be found at the human pharmacy for about 2/3s less than what you pay at the vets. I have spent my entire life having dogs of all sizes and breeds, and have only had to take all my dogs to the vets, after their first year, about once during their lifetime. All my dogs have lived healthy and long lives. All my dogs eat what I eat and never have issues UNLESS THE FOOD IS VERY FATTY, in which case they make many trips to the bathroom, just like any human. If you are a dog owner do some research. That being said the ONE AND ONLY FOOD YOU SHOULD NEVER FEED YOUR DOG IS RAWHIDE BONES. This is due to amount of poisonous chemicals and glues used to make them. Once again go do your research.

  7. I was told by my trusted vet that PRESSED RAWHIDE BONES, MADE IN USA ONLY, are safe for my dogs, regular rawhide swells up in their stomach and causes pain

  8. My 5 year old lab mix accidentally consumed one raisin. I am extremely nervous, should I bring her to the Veterinarian, or should she be fine?


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