If your dog ate grapes, you are rightfully concerned. While certain types of fruit can be beneficial to dogs, some can be more on the risky side. Grapes and raisins can be toxic in dogs and dogs tend to eat them readily due to their sweet, appealing flavors. Left unattended, dogs may therefore eat large amounts straight from the vineyards or straight from the table. Following is some information on grape and raisin toxicity in dogs, symptoms, diagnosis and treatment from veterinarian Dr. Crnec.
My Dog Ate Grapes!
Grapes and raisins, including organic and pesticide-free varieties, as well as seeded and seedless types, can be extremely toxic to dogs. The accent is put on the word can. 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 toxicity while others are not.
Common risk factors associated with grapes poisoning include: owners feeding dogs with grapes/raisins or foods that contain grapes/raisins, grapes left out in fruit bowls, open containers of trail mixes containing raisins, spoiled grapes thrown in the garbage, grapes growing in the garden and wild grapes.
If your dog ate grapes, consider that0 grape varieties are potentially toxic to dogs. That includes: seeded and seedless varieties, organic, home grown, commercially grown and wild grapes, fresh grapes, frozen grapes, dried grapes (raisins) and grape juices and foods containing grape/raisin products.
Did you know? Currants belong in the grape family. According to the Pet Poison Control, currants are moderate to severaly toxic to dogs.
Toxic Dose of Grapes in Dogs
Although generally speaking, the toxic dose is around 32 grams of grapes and 11-30 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.
There are currently 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 toxicity is not fully understood. The only scientifically backed-up data is that the toxicity is not necessarily dose-dependant. This means there is no relationship between the amount of ingested fruit and the severity of the toxic reaction.
Symptoms of Grape/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, diarrhea, presence of grapes or raisins in the stool and/or vomit, dehydration and hypovolemia,loss of appetite, hyperactivity followed by low energy levels, weakness, 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 have transiently increased levels of: serum glucose, creatinine, liver enzymes, pancreatic enzymes, serum calcium and serum phosphorus.
At The Vet’s Office
If your dog ate grapes, your 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 history of exposure (if the owner is aware of what the dog ate) along with clinical 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 and cholecalciferol.
Grape Toxicity Treatment
Unfortunately, there is no specific antidote that can fully reverse the grape’s toxic effects. The treatment is focused on elimination of the toxins, protecting the kidneys while the toxins are still in the circulation and alleviating the subsequent symptoms. Generally, the treatment plan includes:
Decontamination – inducing emesis with 3 percent hydrogen peroxide (2ml/kg but no more than 45ml) followed by administering activated charcoal. This type of decontamination is efficient only if the decontamination occurred within the last two hours.
Other forms of treatment include aggressive intravenous fluid therapy while carefully monitoring the renal function and fluid balance, stimulating the urine production (dopamine, mannitol and furosemide), hemodialysis and peritoneal dialysis (if available), basic symptomatic and supportive therapy (vomiting, diarrhea, seizures), frequent monitoring of blood parameters that indicate renal functioning
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.
The only way of preventing grapes intoxication is by keeping dogs from eating these dangerous fruits. Responsible dog owners must not feed grapes and raisins to their dogs. Fortunately there are many other substitutes to healthy and palatable snacks. Although, up to half of the dogs may not experience intoxication signs, why take the risk? After all, it is always better to be safe than sorry.
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 is a certified nutritionist and is certified in HAACP food safety system implementation.
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.