Feeding the best food to dogs is vital for keeping them healthy and hopefully, leading to longer lifespans. It also means knowing what not to feed them. Many human foods aren’t great for dogs, and some are downright bad.
What about grapes? Are dogs allergic to grapes, or can they be good snacks? While dogs aren’t allergic to grapes, grapes are toxic to dogs.
Here, we discuss why grapes are so toxic to our pets and what you should do if your dog eats any. We also have an FAQ section that might help answer a few questions.
Why Can’t Dogs Eat Grapes?
Grapes are highly toxic to dogs and can lead to kidney failure1 and even death. It’s been difficult for experts to determine what it is about grapes that makes them so toxic, especially since other mammals, like squirrels, can eat them with no real side effects and the toxicity does not necessarily appear dose-dependent in dogs.
In the past it has been theorized that it could be pesticides or a mycotoxin, which is a toxic substance commonly produced by mold and fungus. It’s also been thought that grapes contain a naturally occurring salicylate drug (which is aspirin-like), resulting in decreased blood flow to the kidneys. Current thinking is that it is tartaric acid which is the component of the grape that causes toxicity.
The Journal of the American Veterinary Medical Association published a letter in 2021 from three veterinarians, in which it was hypothesized that tartaric acid and its salt, potassium bitartrate, are the cause of the toxicity. These can vary in concentration in different types of grapes and at different stages of ripening which may explain the inconsistent clinical signs in dogs after grape and raisin ingestion.
There is still more research to be done on this hypothesis. But in the meantime, what we do know is that grapes should never be given to any dog.
What Are the Signs of Grape Poisoning?
Signs of grape poisoning will develop within 24 hours after the dog eats any grapes or grape products. The initial signs may include loss of appetite and lethargy.
As it progresses, signs of kidney failure will occur within 24 to 48 hours and can include the following:
- Uremia breath (might smell like ammonia, urine, or fishy)
- Abdominal pain
- Increased thirst
- Excessive urination
- Decreased or lack of urination
- Mouth ulcers
What Should You Do If Your Dog Ate Grapes?
If you suspect or know that your dog ate any grapes, you should contact your veterinarian immediately for next steps. They will likely want you to bring your pup in for treatment, which might include induced vomiting.
Unfortunately, there is no cure or antidote for grape poisoning, so getting help for your dog before it affects the kidneys is critical!
The vet might also give activated charcoal to your dog, which will absorb the toxins in your dog’s stomach before they are absorbed by the intestines. The sooner your dog is treated for grape poisoning, the better the outcome.
What Is the Prognosis After Grape Poisoning?
Your dog may need to stay at the hospital for up to 48 hours, as the vet will monitor the kidneys and provide intravenous fluids. They may also run blood work to ensure that the kidneys are functioning properly.
The outcome will depend on the level of poisoning and how quickly the dog received treatment. Dogs that ate few grapes and received immediate medical attention will likely recover well.
But if the kidneys are irreversibly damaged and aren’t producing urine, unfortunately, the prognosis is poor. That is why it is essential to seek veterinary treatment straight away if your dog has eaten grapes or raisins.
How Many Grapes Can a Dog Eat Before It Can Be Fatal?
Studies have found that there is a wide range in the amount of grapes and raisins that are needed to be eaten before they cause toxicity and kidney damage. To complicate things further, different dogs appear to respond differently after eating grapes. This may be due to the differing amounts of tartaric acid in different types of grapes but more research is needed.
At this point there are still many unknowns and as toxicity does not always appear to be dose related, if your dog ingests any grapes or raisins at all you should contact your vet or the pet poison helpline immediately.
Can Dogs Eat Raisins?
No! Nothing related to grapes, which includes raisins, currants, and sultanas, should be fed to your dog. It’s also thought that the dried versions of grapes are more concentrated and therefore toxic than fresh grapes.
What Kind of Grapes Are Toxic to Dogs?
Foods containing grapes, raisins, and currants, such as raisin bran cereal, granola, trail mix, and baked goods, should also be avoided.
How Can You Prevent Your Dog From Eating Grapes?
Besides simply not feeding any to your dog, you must be vigilant when handling grapes or any other toxic food. Grapes should be stored in the fridge, and shelf-stable foods should be in jars with screw-top lids in high cupboards. If you need to store any of these foods in lower cupboards and your dog is too smart for their own good, place childproof locks on the doors.
Also, try to be aware of all the different products that you have that contain raisins, such as granola bars and cookies, and don’t leave them sitting around. Speak to everyone in the family about the rules for grapes and grape products.
What Other Foods Are Toxic to Dogs?
Besides grapes and raisins, other foods are toxic to dogs:
- Xylitol (sugar substitute)
- Macadamia nuts
Foods with high amounts of sugar and fat can become toxic over time by causing health conditions like obesity and pancreatitis.
What Are Safe Fruits for Dogs?
There are a few fruits that are quite safe for dogs, albeit in moderation:
- Apples (core and seeds removed)
- Pears (core and seeds removed)
- Oranges (peel and seeds removed)
- Bananas (skin removed)
- Peaches (pit removed)
- Pineapples (skin removed)
- Strawberries (stem removed)
- Watermelon (peel and seeds removed)
Always remember to wash the fruit thoroughly. Also, while fruit is healthy, it’s high in sugar and can lead to weight gain. Dogs with diabetes should avoid sweet foods altogether.
The most important takeaway here is that you should always consider human foods that you give your dog as treats and that you should always research a food before giving it to your dog. Grapes are healthy treats for us and a few other mammals but are dangerous for dogs.
Not all human foods are options for dogs, so consulting with your vet before you give them something new is always a good idea. This is particularly vital if your dog has an existing condition!
Also, remember to speak to your family and any guests about foods in the house that are off-limits to your dog and why. Your dog’s safety is far more important than providing them with a delicious treat.