My dog ate grapes — how bad is it?
Estimate exposure dose from grape weight + your dog's body weight. Severity bands per ASPCA/Pet Poison Helpline. Call a hotline even on "below threshold" doses — grape sensitivity is individual.
Dose (g/kg) = grapes_eaten_g / dog_weight_kg No proven safe dose. Clinical concern begins around 11 g/kg; Eubig 2005 documented AKI at 0.7 oz/lb (~32 g/kg), with sporadic case reports far below this — ASPCA APCC treats any ingestion as a decontamination case.
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Signs to watch for
Why grapes are dangerous
The mechanism is now believed to be tartaric acid (and potassium bitartrate) in grapes, which causes acute kidney injury in dogs — but humans, cats, and most other species are unaffected. Why dogs are uniquely sensitive remains unclear. What's clear: sensitivity varies enormously between dogs. There are case reports of severe injury from a single grape, alongside reports of dogs eating handfuls without symptoms.
What treatment looks like
For exposures within 2 hours: induced vomiting + activated charcoal to block absorption. IV fluids for 48–72 hours to support the kidneys and flush the toxin. Bloodwork (BUN, creatinine, electrolytes) monitored daily. Most dogs recover fully when treatment starts before kidney values rise.
Sources: ASPCA Animal Poison Control Center. Pet Poison Helpline. Eubig PA, et al. "Acute renal failure in dogs after the ingestion of grapes or raisins." J Vet Intern Med (2005). Wegenast CA et al. "Acute kidney injury in dogs following ingestion of cream of tartar and tamarinds." J Vet Intern Med (2022).
Frequently asked questions
How toxic are grapes to dogs?
Highly toxic — and unpredictably so. Some dogs develop acute kidney injury after eating just a single grape; others tolerate larger amounts. The mechanism is now thought to involve tartaric acid, but individual sensitivity is huge. The veterinary recommendation: treat any ingestion as worth a hotline call, regardless of dose.
How many grapes is too many?
There is no proven "safe" dose. Documented clinical cases of acute kidney injury have occurred with as little as 0.7 oz of grapes per kg of body weight. For a 10 kg (22 lb) dog, that's about 7 oz (200 g) — roughly a small handful. But because sensitivity varies, the safest answer is "no grapes ever."
How fast do symptoms appear?
Vomiting often within 6–24 hours. Kidney injury (lethargy, decreased urine, increased thirst) within 24–72 hours. Early treatment is far more effective than late — call a hotline within the first 6 hours if at all possible.
What about raisins?
Raisins are dried grapes — far more concentrated and proportionally more toxic by weight. The threshold for raisins is roughly one-quarter of the grape threshold. See our raisin toxicity calculator for raisin-specific math.