One grape is not a dose anyone can look up. Veterinary medicine has never set a toxic threshold for grapes or raisins in dogs or cats, and reported cases sit on both sides of every guess: dogs that developed acute kidney injury (AKI) after a handful of raisins, and dogs that ate far more and stayed normal. That single gap should drive the whole response. Treat any ingestion as an exposure, do not wait for symptoms, and keep the packaging.
Why no threshold exists, and what replaces it
The leading suspect is tartaric acid and its salt, potassium bitartrate, which make up roughly 0.5 to 1.5 percent of grape flesh by weight. Ripeness, variety, and drying all move that figure, and individual animals appear to handle it differently. Cats are affected too; published reports are fewer, but the injury pattern is the same. In practice a 30 kg dog that ate 2 raisins and a 4 kg cat that licked up 1 grape belong in the same phone call, made within the same hour. The missing number is not permission to wait 6 hours and see what happens.
1 raisin is 3 to 4 grapes
Drying removes water, not the compound you are worried about. 100 g of fresh grapes becomes about 25 to 30 g of raisins, so each raisin carries the load of roughly 3 to 4 grapes, and a 40 g snack box equals 120 to 160 g of fresh fruit. Currants and sultanas are the same fruit under other names. One slice of raisin bread usually holds 25 to 35 g of raisins, and a 50 g handful of trail mix can be 40 percent raisins by weight. Count what is missing rather than what was eaten: a 500 g bunch that now weighs 380 g means 120 g gone, which is a different conversation from 1 grape.
The 2-hour window is the only early clock
Stomach emptying by a veterinarian is only useful in roughly the first 1 to 2 hours after ingestion, and the value drops fast after that. Never make a pet vomit at home. Aspiration, salt poisoning, and injuries from sharp food are all common outcomes, and the cleanup delays real care by 30 to 60 minutes. Call instead and give 4 facts in this order: species, body weight in kg, estimated amount, and the time it happened. Ask directly whether the clinic wants the animal now. A hospital that has the right support on hand can start intravenous fluids within 30 to 60 minutes of arrival.
Hours 0 to 24: 3 signs worth writing down
Vomiting, usually 1 to 8 episodes and often inside the first 6 hours; lethargy that is clearly out of character; and urine output falling. Normal urine production is 1 to 2 ml per kg per hour, so a 5 kg cat should pass roughly 60 to 120 ml in 12 hours. With a litter box, count clumps and weigh 3 of them once to calibrate. A dog that has not urinated in 12 hours, or a cat with no clumps in 8, needs to be seen even if it looks bright and is still eating.
Days 2 and 3: the numbers that define kidney injury
Creatinine and blood urea nitrogen (BUN) can be normal at hour 12 and abnormal at hour 48. Recheck at 24, 48, and 72 hours, and ask for the values in writing so you can compare them yourself. Hospitalized cases typically run fluids at 2 to 3 times maintenance for 48 to 72 hours, then taper. A pet with normal creatinine, concentrated urine, and normal urine output at 72 hours has usually cleared the window. One with a rising creatinine at 48 hours needs another 24 to 48 hours of support and a repeat panel before discharge.
5 things to bring or photograph
- The packaging with the lot code and net weight, because batch questions come up later.
- The remaining bunch or box, weighed on a kitchen scale in grams.
- The time of ingestion, written down, not reconstructed from memory at hour 5.
- A photo of any vomit with a coin or ruler in frame for scale.
- The pet's last known weight, or a weigh-in at the clinic before treatment starts.
Foods that hide grapes and raisins
Trail mix, granola and cereal bars, panettone, hot cross buns, oatmeal cookies, mincemeat, some curries, and a long list of dog treats and jerky. Grape juice concentrate and grape pomace show up on labels without the word grape anywhere in the product name. Read 3 lines of the ingredient panel: raisins, currants or sultanas, and juice concentrate. A 250 ml glass of grape juice represents roughly 300 g of fruit, which is why open juice is not something to leave out in a house with a 3 kg cat and a 25 kg dog.
Exposure, action, and monitoring window
| What was eaten | Fresh-fruit equivalent | Call the vet within | Monitoring |
|---|---|---|---|
| 1 grape, about 5 g | 5 g | 1 hour | 72 hours |
| 1 raisin, about 0.7 g | 2 to 3 g | 1 hour | 72 hours |
| 40 g raisin box | 120 to 160 g | immediately | 72 hours |
| 1 slice raisin bread, 30 g raisins | 90 to 120 g | 1 hour | 72 hours |
| 250 ml grape juice | about 300 g | 1 hour | 72 hours |
| Half of a 500 g bunch | 250 g | immediately | 72 hours |
Use the middle column when the owner only knows the fruit, not the dried weight. Both columns describe the same exposure, and both land in the same 72-hour window. A one-page version of this table sits on the toxin tool.
When to skip the call and drive
Go now for no urine in 12 hours, vomiting more than 6 times, gums that look pale or brick-colored, a temperature under 37.5 C, or any tremor. Do not wait for all of those to line up. Bring the pet's own water bowl if the visit runs overnight, because a hospital that can measure intake and output from hour 1 has better numbers to work with at hour 48, when the decisions actually get made.
5 steps for tonight
- Weigh what is left and write down the time and the pet's weight on one sheet of paper.
- Call the clinic, say the 4 facts, and ask whether to come in now or at hour 4.
- Photograph the packaging, the bunch, and any vomit before cleaning anything up.
- Collect the next urine sample in a clean container if the pet will allow it, and note the time.
- Book the 24, 48, and 72 hour rechecks before you leave the building, so the 3 day window is not lost to a busy week.
For a full list of household exposures ranked by urgency, keep the household toxin checklist open while you call, and use the same page when a second pet in the house has already shared the bowl.
Terms mentioned in this article
Frequently asked
My 25 kg dog ate 2 raisins. Is that really an emergency?
Yes, a phone call is warranted within the hour. No toxic dose has been established for raisins, and reported cases include animals injured by very small amounts. The vet will weigh the exposure against the 1 to 2 hour decontamination window, then set a 72 hour plan with creatinine and urine output checks at 24, 48, and 72 hours.
Can I just watch for vomiting and skip the clinic?
No. Vomiting is often absent in the first 6 hours, and the kidney values that matter can be normal at hour 12 and abnormal at hour 48. Waiting until a dog looks sick usually means arriving after the useful decontamination window has closed, which shifts care toward 48 to 72 hours of fluid support instead of a simple early intervention.
Do raisins in baked goods count?
Yes, and the numbers add up quickly. One slice of raisin bread holds 25 to 35 g of raisins, which equals roughly 90 to 120 g of fresh grapes. Trail mix can be 40 percent raisins by weight. Treat any product listing raisins, currants, sultanas, or grape juice concentrate as an exposure and keep the packaging for the vet.