As a pet parent, you may have heard that grapes are a no-go for dogs. And it's true! While grapes are a healthy and delicious snack for humans, grapes and their dehydrated relative, raisins, are off limits for pups. But why are grapes bad for dogs? Learn more about how grapes can harm you furry family members.
Why Are Grapes Bad for Dogs?
According to the Journal of Veterinary Internal Medicine, the primary internal injury in dogs from grapes occurs in the kidneys. In fact, dogs who have snacked on grapes or raisins are at risk of total kidney failure within 48 to 72 hours of eating this forbidden fruit.

Because of their decreased water content and concentrated remaining ingredients, raisins do pose a considerably heightened risk to dogs. An exact formula of how many grapes per pound of body weight are fatal to dogs has not yet been determined, but as few as four to five grapes were implicated in the death of an 18 lb (8.16 kg) dog, according to Merck Veterinary Manual.
My Dog Ate Grapes: What Symptoms Should I Watch For?
Most affected dogs develop the first signs of toxicity within 6 to 12 hours. Clinical signs that may occur after a dog has eaten grapes include:
- Vomiting
- Diarrhea
- Extra jittery in the early stages
- Lethargy as time passes
- Anorexia
- Abdominal pain
- Weakness
- Dehydration
- Increased urination in early stages
- Shivering
- Not urinating as the kidneys shut down
All dogs are susceptible to grape and raisin toxicosis — whether they're male or female, neutered or intact, Chihuahuas or Great Danes, puppies or senior dogs. Ingestion of only a few raisins can be deadly, depending upon your dog's size and other factors, many of which are not understood. Dogs with compromised kidney conditions are more at risk for grape and raisin toxicity.