If your dog ate raisins, you are right to be concerned: raisins can be toxic to dogs and you certainly don't want a simple dietary indiscretion to turn into something potentially dangerous. Unfortunately, dogs are quite gluttonous beings and they will devour anything that attracts them and this often includes unsafe foods such as chocolate, sweets containing the artificial sweetener xylitol and yeast dough just to name a few. Fortunately, if you just caught your dog eating raisins, the good news is that your vet can provide you with guidelines on how to induce vomiting. In this article, veterinarian Dr. Ivana Crnec provides details about raisin toxicity in dogs.
Help My Dog Ate Raisins!
Black or white, organic or conventionally grown, pesticide free or pesticide contaminated, seeded or seedless, fresh or dried, raw or cooked, grapes and raisins can be extremely toxic to dogs. The accent is put on the word can. Indeed, it is an interesting fact that not all dogs are sensitive to grapes and raisins. Newer scientific data suggest that some dogs are genetically predisposed to grapes/raisins toxicity while others are not. It is also undetermined which substance in the fruit is responsible for triggering its toxic effect.
The toxic dose is around 32 grams of grapes and 11 to 30 grams of raisins per kilogram of the dog’s body weight, some dogs are capable of eating significantly larger amounts without displaying any signs of intoxication. On the flip side, in some dogs, only 2 to 3 pieces are enough to cause poisoning.
On a per-weight basis, raisins are approximately 4.5 percent more concentrated than fresh grapes. Therefore, raisins are more toxic than grapes. With this in mind, it's important to prevent exposure. Common risk factors associated with grapes/raisins poisoning include: owners giving grapes/raisins or foods that contain grapes/raisins to their dogs (unaware of the possible consequences), grapes/raisins left out unattended in fruit bowls, open containers of trail mixes containing raisins, spoiled grapes/raisins thrown in the garbage, grapes growing in the garden, wild grapes and wine.
It should be noted that dogs like the sweet taste of grapes. Therefore, if given the opportunity, dogs will voraciously consume grapes/raisins including seeded and seedless varieties, organic, home grown, commercially grown and wild grapes, fresh grapes, frozen grapes, dried grapes raisins (black grapes) and sultanas (white grapes), grape juices and foods containing grape/raisin products, currants (which belong in the grapes family)
As mentioned, there are no reported breed, age or gender predispositions to developing grape toxicity. However, it is safe to assume that dogs already suffering from kidney diseases are at higher risk of developing acute renal failure.
Unfortunately, the exact mechanism of grapes/raisins toxicity is not fully understood. The only scientifically backed-up data is that the toxicity is not necessarily dose-dependent. This means there is no relationship between the amount of ingested fruit and the severity of the toxic reaction. This is mostly due to the fact that some individuals are sensitive while others can tolerate grapes/raisins.
Symptoms of Raisin Toxicity in Dogs
Data collected from veterinary clinics show that dogs manifest initial signs of intoxication 6 to 12 hours after indigestion. The ultimate effect, anuric renal failure, develops within 72 hours of indigestion. The term anuric renal failure describes kidney impairment that leads to inability to produce urine and excrete waste products. The retained waste products accumulate in the dog’s body and lead to detrimental effects.
Grapes intoxication in dogs manifests with:
- vomiting (with or without blood)
- diarrhea (sometimes tinted with blood)
- presence of grapes or raisins in the stool and/or vomit
- dehydration and hypovolemia
- loss of appetite
- excessive drooling
- hyperactivity followed by low energy levels
- lack of coordination (wobbly walk)
- signs of abdominal pain
- excessive thirst and increased water intake (polydipsia)
- tremors (shivering)
- difficult breathing
- lack of urine production (anuria).
On a blood analysis, affected dogs show transiently increased levels of: serum glucose, creatinine, liver enzymes, pancreatic enzymes, serum calcium and serum phosphorus.
At the Vet's Office
The vet will perform a full and thorough clinical examination of the dog, including routine blood works and urine analysis. The final diagnosis is based on exposure history (if the owner is aware of what the dog ate) andclinical signs.
Once the diagnosis is set, the veterinarian will perform an abdominal radiography and ultrasound to determine the kidneys’ size and structure. The vet may also advise kidney biopsy to assess the nature and extent of kidney damage.
In the differential diagnosis, other causes of renal failure must be taken into consideration. Common differential diagnosis include: poisoning with ethylene glycol or poisoning with cholecalciferol.
If your dog ate raisins what is the treatment? Unfortunately, a specific antidote that can fully reverse the grapes/raisins toxic effects does not exist. Instead of full reversal, the treatment focuses on 3 important goals: 1) elimination of the toxins, 2) protecting the kidneys while the toxins are still in the circulation and 3) alleviating the subsequent signs and symptoms.
Generally, the treatment plan of grape toxicity in dogs includes:
Decontamination – inducing emesis with 3% hydrogen peroxide (2ml/kg but no more than 45ml) followed by administering activated charcoal. This type of decontamination is efficient only if the grapes/raisins ingestion occurred within the last two hours.
Aggressive intravenous fluid therapy while carefully monitoring the renal function and fluid balance.
Stimulating urine production (administration of diuretics such as dopamine, mannitol and furosemide).
Hemodialysis and peritoneal dialysis (if available).
Basic symptomatic and supportive therapy (management of vomiting, diarrhea, seizures).
Frequent monitoring of blood parameters that indicate renal functioning.
Sadly, if the intoxication has progressed to the stage of impaired or non-existing urine production, the prognosis is guarded to poor. However, in some cases, depending on the severity of the intoxication, given time and aggressive supportive treatment, the kidney damage can be reversed.
An Ounce of Prevention is Worth a Pound of Cure
Although, up to half of the dogs may not experience intoxication signs, why taking the risk. The only fully efficient way of preventing grapes/raisins intoxication is by keeping dogs from eating these dangerous fruits.
Knowing which human foods are safe for your canine baby is part of being a responsible dog parent. If you are not sure whether certain human food can be fed to dogs, do not hesitate to consult with your trusted vet. Fortunately, there are many other substitutes to healthy and palatable human snacks for dogs.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.
She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.
Ivana’s research has been published in international journals, and she regularly attends international veterinary conferences.