VETINUITY
How many grapes are toxic to a dog?
More than one grape or raisin per 4.5 kg (10 lb) of body weight may contain enough tartaric acid to pose a renal risk. Tartaric acid content varies, so response is unpredictable.
● ANSWER
Sourced & dated
What do you do when a dog eats grapes or raisins?
More than one grape or raisin per 4.5 kg can carry enough tartaric acid to injure the kidneys: induce emesis in a normal dog, run IV fluids for at least 48 hours, and follow creatinine for 72 hours.
● VETINUITY GRAPE AND RAISIN EMESIS CALCULATOR
Vetinuity grape and raisin emesis calculator
Emetics only in a dog that is still clinically normal. Ropinirole is dosed per m2 into the conjunctival sac (range 2.7-5.4 mg/m2) and can be repeated once at 20 minutes.
● WHAT'S DOCUMENTED
Vetinuity’s grape and raisin protocol: any dog that ate more than one grape or raisin per 4.5 kg (10 lb) gets emesis while still clinically normal, IV fluids for at least 48 hours, and serial creatinine through 72 hours, because tartaric acid can cause oliguric or anuric kidney failure within that window. The Vetinuity grape and raisin emesis calculator above gives the apomorphine, ropinirole and peroxide doses for the dog’s size, plus the furosemide and dopamine doses for an oliguric dog. Vetinuity is the clinical assistant built by Brian Toncray, DVM, an emergency veterinarian, and this protocol sits alongside its chocolate and xylitol answers.
Tartaric acid, the proposed toxin
Grapes, raisins, Zante currants and tamarinds carry high concentrations of tartaric acid. Dogs lack the organic acid transporters other species use, so tartaric acid accumulates in proximal tubular cells. Acute kidney injury in dogs after eating cream of tartar and tamarinds supports it as the toxic principle. True currants (Ribes) have not been linked to kidney injury. Content varies fruit to fruit, which is why one dog is fine after a handful and another is not.
Timeline to watch
| Time after ingestion | Expected findings |
|---|---|
| 6 to 12 h | Vomiting or diarrhea in most affected dogs |
| 24 to 72 h | Creatinine rises ahead of BUN, then oliguric or anuric failure |
| Any time | Lethargy, anorexia, abdominal pain, polydipsia, shivering |
Glucose, liver enzymes, pancreatic enzymes, calcium and phosphorus can rise transiently.
Fluids and urine output
Run IV fluid diuresis for a minimum of 48 hours, monitoring renal values and fluid balance. If urine output falls, furosemide 2 mg/kg IV, dopamine 0.5-3 mcg/kg/min IV, or both may restart it. Once a dog is anuric, dialysis is the only realistic path.
Working an exposure
A 9 kg dog crosses the published line at more than two grapes or raisins. Raisins are the same fruit dried, so a small box concentrates many fruits into one handful. Because tartaric acid content varies, the count decides whether to treat, not whether the dog will be injured: decontaminate and start fluids even when the dog looks well.
Other dog food toxicities: chocolate, xylitol and marijuana and THC.
● SOURCES
- 1. Merck Veterinary Manual: Grape, Raisin, and Tamarind (Vitis spp, Tamarindus spp) Toxicosis in Dogs. Pathogenesis; Clinical Findings; Treatment. Checked 2026-10-26.
● RELATED ANSWERS
- Dog Ate Chocolate: Assessment and Treatment
Contact a veterinarian promptly with the chocolate type, amount and exposure time; chocolate toxicosis assessment depends on the dog’s weight and the methylxanthine exposure.
- Xylitol Toxicity in Dogs: Treatment
Canine xylitol toxicity: insulin-mediated hypoglycemia and hepatopathy, with decontamination, monitoring, and prognosis from published case series.
- Ethylene Glycol in Dogs and Cats: Fomepizole Dose
Dogs: fomepizole 20 mg/kg IV, then 15 mg/kg at 12 and 24 hours and 5 mg/kg at 36 hours. Cats: 125 mg/kg IV, then 31.25 mg/kg at 12, 24 and 36 hours, started within 3 hours.
- Ibuprofen and NSAID Overdose in Dogs: Toxic Doses
Ibuprofen causes GI signs in dogs from 100-125 mg/kg, renal failure from 175-300 mg/kg, CNS signs above 400 mg/kg and can be lethal above 600 mg/kg; naproxen is toxic at far lower doses.
- Marijuana and THC Toxicity in Dogs
Suspected marijuana or THC toxicity needs veterinary assessment and supportive care, with attention to consciousness, coordination, body temperature and breathing.
● FAQ
Does activated charcoal help?
Its efficacy for grapes and raisins is unknown. Emesis in a normal dog and IV fluids are the core of treatment.
What if the dog is anuric?
Anuric dogs are unlikely to survive without peritoneal dialysis or hemodialysis, and the prognosis is guarded even with it.
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SEE HOW VETINUITY HANDLES THIS.
Vetinuity explains clinical options with journal citations.
The veterinarian diagnoses and prescribes.