Grapes and raisins: toxic to dogs
Grapes and raisins can cause severe kidney failure in dogs. Why they are toxic, which symptoms occur and what to do immediately.
Short & honest
Grapes and raisins are proven toxic to dogs (evidence level B): even small amounts can cause acute kidney failure. Always consult a vet immediately after ingestion — never wait for symptoms.
Safety assessment: Toxic — do not use
Veterinary review not yet completed
This page is awaiting review by a registered veterinary surgeon. Until then, treat the text as education based on the sources listed — not as a verified veterinary judgement.
Why are grapes and raisins toxic to dogs?
The exact toxic substance has not yet been identified. Pesticides, fungi and the grape variety have been investigated as explanations, but no single mechanism fully explains the toxicity [1]. This also applies to organic or home-grown grapes without pesticides — these are also not safe [2]. Dried variants (raisins, currants, sultanas) are at least as dangerous as fresh grapes; due to the lower weight, a small amount contains more potentially harmful substance per gram.
There is no safe lower limit
No safe dose has been established. Some dogs become seriously ill from a handful of raisins; in others, a similar amount appears to have little effect. Because this variability is unpredictable, any contact is considered potentially serious and requires immediate veterinary advice [1][2].
Symptoms of poisoning
Symptoms can develop within 6 to 12 hours after ingestion, sometimes later:
- Early phase (first hours): vomiting, diarrhoea, lethargy, reduced appetite, abdominal pain
- Later phase (24–72 hours): severely reduced or absent urine production, dehydration, weakness, trembling
- Severe: acute kidney failure — a life-threatening complication that can also occur without clear early symptoms [1][2]
The absence of early complaints does not mean that no damage is occurring. Do not wait for symptoms.
Products to be alert to
| Product | Risk assessment |
|---|---|
| Fresh grapes | High |
| Raisins | High (concentrated weight) |
| Currants / sultanas | High |
| Raisin bread, cake, muesli, trail mix | High |
| Grape juice or extract | Unknown — not safe |
What to do in case of (suspected) ingestion?
Contact a veterinary surgeon or poison control line immediately — even if the dog is not yet showing symptoms. The earlier treatment begins, the greater the chance of recovery [2].
Bring the following to the consultation:
- Which product (grape, raisin, pastry with raisins)?
- Estimated amount and time of ingestion
- Weight of the dog
Treatment may consist of inducing vomiting (only safe in the early stage and feasible by a veterinary surgeon), activated charcoal and intravenous fluid therapy to protect the kidneys [2]. Never attempt to induce vomiting yourself without veterinary supervision.
'Natural' does not equal 'safe'
Grapes are an unprocessed, plant-based product — and yet one of the most serious food poisonings in dogs. The origin or 'natural' status of a substance says nothing about its safety for a specific animal species. This distinction is crucial when assessing any dietary advice for dogs.
Other animal species
The described toxicity is specific and documented for dogs. For cats and other pets, no comparable evidence exists, but exposure is also discouraged in these animals [1].
Why this verdict?
The evidence level is B (reasonable evidence): toxicity is consistently documented in case reports, poisoning notifications and retrospective clinical series [1][2]. A controlled prospective study is lacking and the active toxic substance has not been identified to date, leaving the precise dose-response relationship unknown. The fact that some dogs react to small amounts while others apparently do not makes assessment of individual risk impossible — which increases the value of precaution.
Legal status (Netherlands)
Treatment of poisoning in animals is reserved for veterinary surgeons in the Netherlands (Wet dieren). This page is for information only and does not replace a veterinary consultation.