10/11/2023
A recent opinion piece stated, ‘Has your dog eaten raisins? The Yorkshire Vet says you don't need to panic’. Sorry, but we suggest differently. Panic? No. A sense of urgency and immediate veterinary care? Yes.
Raisins are toxic, but unfortunately it is not always as simple as other toxicities where we have a known dose that can cause an issue. Unfortunately, we do not yet know exactly what causes this toxicity and the risk to dogs doesn’t depend on the amount eaten or size of dog.The Veterinary Poisons Information Service and Animal PoisonLine (VPIS) say that the prognosis is good if treatment is started promptly as this will protect the kidneys. Prognosis is more guarded in pets that go to the vet surgery later and already have signs of kidney damage.
So, what's the confusion? ASPCA and two veterinary hospitals in the United States identified tartaric acid and its salt, potassium bitartrate (also known as cream of tartar), as the possible culprit. The link, while promising in theory, hasn't been definitively proven.
So, despite the development that it could be Tartaric acid, the advice on what to do is still the same as we are still understanding the possible link. A group of veterinary surgeons from the ASPCA Animal Poison Control Center and two hospitals describe in a letter to the editor in the Journal of the American Veterinary Medical Association that tartaric acid may be the part of grapes that cause them to be toxic to pets. This can explain why we don't always see a 'dose' dependent reaction. The amount of tartaric acid can vary in grapes by their type, how they were grown, and how ripe they are, which could explain why some pets get very sick, whilst others seem unaffected after eating similar amounts of grapes or raisins.
Several reports of dogs developing acute kidney injury (AKI) after ingestion of grapes, raisins, or currants have been published. Reported clinical signs typically include vomiting within 24 to 48 hours of ingestion, with vomitus or diarrhea fluid possibly containing grapes or swollen raisins. Other signs were compatible with acute uraemia and included anorexia, lethargy, diarrhoea, and abdominal pain, as well as oliguria or anuria in 49% of dogs. Azotemia developed rapidly within 2 days of ingestion. A clear dose response relationship has not been determined.
When polled about their level of concern when dogs eat grapes 74% of vets were either highly or moderately concerned.
If you dog has ingested anything with raisins in, you need to call your Veterinary practice straight away.
They may want to:
✅Offer to induce emesis (vomiting)
✅Test your dog's kidney parameters with a blood sample that may need repeating a number of times
✅Start them on aggressive intravenous fluid therapy
✅They may require hospitalisation for a number of days
Now here is the crux, it is up to you how you deal with your dog eating raisins. Many times, a dog may eat raisins and be absolutely fine. Other times, a small amount could be enough to cause an acute kidney injury.
Veterinary teams do not have a crystal ball to tell us which way it will go, we can only offer the treatment options for the ‘worst case scenario’. If you decide not to treat it, then it is a possibility that your dog may develop acute kidney failure and after this point the treatment is much harder.
Although it might seem excessive, in the absence of a way to test for the toxic agent in different grapes, we do not know a reliable enough ‘dose’ to give your dog the ‘all clear’ after even a small amount of raisin ingestion.
So, should you panic? No, we don’t recommend panicking in any emergency situation. But do we advise swift, urgent and immediate veterinary attention? Yes, we do.
esms_3016-apl-grapes-dl-sep18-1.pdf (vpisglobal.com)
Veterinarians weigh grape poisoning risk - News - VIN
Toxicosis with grapes or raisins causing acute kidney injury and neurological signs in dogs - PMC (nih.gov)
Letters to the Editor in: Journal of the American Veterinary Medical Association Volume 258 Issue 7 (2021) (avma.org)