Grape
ToxicGrapes cause idiosyncratic acute kidney injury in dogs. No safe dose exists, and Merck puts the risk threshold at more than one grape per 4.5 kg (10 lb) of body weight.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Do not offer as a treat
There is no recommended treat portion for this hazardous item. If swallowed, contact a vet with the amount, time and product details. Do not induce vomiting yourself.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Vomiting
- Diarrhoea
- Loss of appetite
- Lethargy
- Abdominal pain
- Increased thirst
- Raised nitrogen waste in blood
- Tremors
More about this food
For decades nobody could explain why grapes destroyed some dogs' kidneys and left others fine. Since 2021 the leading hypothesis is tartaric acid and potassium bitartrate: dogs lack a functional renal OAT4 organic-anion transporter, so tartaric acid accumulates inside proximal tubular cells and kills them. That is why this is acute kidney injury rather than an upset stomach.
The practical number to hold onto is Merck's: risk begins above one grape per 4.5 kg of body weight. A 22 lb (10 kg) dog crosses it at three grapes. Older literature quoting 19.6-32 g/kg is background only, because tartaric acid content swings with variety and harvest lot -- typically 0.35-1.1% and as high as 2% -- so no threshold can be called safe. In the US this matters most around fruit trays, Thanksgiving and Fourth of July spreads, chicken or Waldorf salads, kids' lunchbox grapes on the floor, and grape juice. Seedless, organic, red, green, and peeled grapes are all included; so are raisins, currants and sultanas, and Merck's September 2024 revision folded tamarind into the same monograph.
Timing is the trap. Vomiting, diarrhea, anorexia and lethargy usually appear within 6-12 hours, but azotemia and kidney failure show up at 24-72 hours. A dog that looks normal at bedtime is not out of danger.
Call your veterinarian or an emergency animal hospital now, or the ASPCA Animal Poison Control Center at (888) 426-4435 -- a consultation fee applies, and they will give your vet a case number. Note the amount, the time, and the variety. Do not induce vomiting at home with salt or hydrogen peroxide. Decontamination, activated charcoal, and 48-72 hours of IV fluids with serial kidney values are veterinary decisions.
Frequently asked questions
- My dog ate one grape. Is that an emergency?
- For a dog under 10 lb (4.5 kg), a single grape already exceeds Merck's risk threshold of one grape per 4.5 kg. For larger dogs there is still no dose proven safe, so call your vet or the APCC at (888) 426-4435 with your dog's weight and the time of ingestion.
- Are seedless or peeled grapes any safer?
- No. Tartaric acid is in the grape flesh itself, and no study separates safe parts from dangerous ones. Seedless, peeled, organic, red and green grapes are all treated the same way, as are grape juice and grape jelly.
- He ate them six hours ago and seems totally fine. Can I wait?
- Looking fine at six hours proves nothing, because the kidney injury shows as azotemia at 24-72 hours, well after the GI signs. Waiting for symptoms means starting IV fluids after the damage has already begun, so call now instead.