We Know Grapes Are Bad For Dogs … But Why?

are grapes bad for dogs

Dogs love human food. And there are lots of whole foods that are safe to share with your dog … but grapes aren’t one of them.

Grapes can be very dangerous for dogs. Even a grape or two can lead to sickness … or death.

But that doesn’t mean all grape products are off the table.

Today I’ll talk about grapes and grape products. But first I want to share an interesting fact with you …

Grapes And The Wild Canine Diet

Did you know that some wolves eat grapes?

Dr Isla Fishburn is a zoologist, wellness practitioner, conservation biologist and shaman. She’s researched wolves for many years. And she uses what she learns to help dogs and owners.

In 2016, she spoke at Raw Roundup about the wild canine diet and how it translates to your dog’s diet.

“What’s really interesting is that we’ve observed individual wolves who will eat a range of vegetable matter … including fruits, grasses, seeds, sedges and berries. Fruits include plums, pears, blackthorn, acorns and GRAPES! So there’s vegetation going into some wolves, but not all wolves. It’s an amazing observation and leads to more questions about why this is happening. Is it nutritional? Is it medicinal (like parasite control)? Or is it because wolves have knowledge about functional foods and carbohydrates?”

It’s true that experts disagree about the best diet for dogs, but Dr Fishburn believes …

“The best diet needs to vary from individual to individual. We need to focus on diets for dogs as individuals – weight, breed, age, exercise, individual preferences … “

Which could explain why some dogs have a more severe reaction to grapes than others. Let’s dive a bit deeper into that …

Why Are Grapes Bad For Dogs?

Grapes kill dogs. You know that. And that’s because grapes can cause kidney failure.

But outside of that, grapes are a bit of a mystery.

They’re toxic but researchers have yet to figure out why. They also don’t know if there’s a safe number of grapes dogs can eat …

Some dogs seem fine after a couple of grapes while others have quick and severe reactions.

And that may go back to what Dr Fishburn recommends – diets based on the individual dog, not the species.

But …

Because there’s little proven research behind grapes … I recommend you never feed your dog any part of a grape or raisin. Raisins are riskier because they’re dried, which concentrates the constituents.

Signs Your Dog’s Sick From Grapes

Sometimes accidents happen and your dog eats a grape or raisin.

If you think your dog ate grapes or raisins, watch for these signs of toxicity

  • Loss of appetite
  • Weak or still
  • Vomit
  • Diarrhea
  • Tender when touched in the abdomen
  • Dry nose
  • Dry gums
  • Pale gums
  • Panting
  • Thirsty
  • Increased urine production
  • Low or no urine production
  • Kidney failure

Is Grapeseed Oil Safe For Dogs?

Grapeseed oil comes from the seeds of grapes but … it’s not toxic for dogs.

That doesn’t necessarily mean it’s safe. There’s one main caution you should take.

Grape seed oil is high in linoleic acid (LA), a polyunsaturated omega-6 fatty acid. This essential fatty acid helps with cell membrane structure and cell function. LA also plays a role in …

  • Immune function
  • Skin and coat health

But too much omega-6 can lead to increased inflammation. And that can cause immune dysfunction and chronic issues like …

  • Diabetes
  • Liver and kidney disease
  • Allergies
  • Inflammatory bowel disease
  • Cancer

That’s why you must balance your dog’s omega-6 intake with his omega-3 intake.

And this is where you must be careful with grapeseed oil …

Modern diets are already high in omega-6. If you add more, it can amplify the imbalance.

When Your Dog Needs More Omega-6s

Whether you need to add omega-6 to your dog’s diet depends on his current diet.

Kibble and Processed Food

Kibble and other processed food don’t just contain unbalanced animal fats. To keep costs low, they also contain grain and other foods with unbalanced fats.

Manufacturers of pet food must meet AAFCO standards. Otherwise they can’t advertise their food as balanced. But …

… the ratio for omega-6 to omega-3 only gets flagged if it exceeds 30:1.

That means there’s a risk that your dog’s food is too high in omega-6.

If your dog eats kibble, you’ll want to add more anti-inflammatory foods.

Ruminants Like Beef

Ruminants have four stomachs and include …

  • Cows
  • Sheep
  • Goats
  • Buffalo
  • Deer
  • Elk

If you feed your dog ruminants, he’ll need more LA and alpha-linolenic acid (ALA).

(ALA is an omega-3)

While grapeseed oil is high in LA, it isn’t high in ALA.

Instead, use hempseed oil. It’s a better option to balance out the fats because it has an ideal ratio of LA and ALA.


Poultry’s high in LA (the main fatty acid in grapeseed oil). That means your dog doesn’t need any more LA if he eats poultry.

Instead you will want to add ALA rich oil like chia seed oil or try sardines.

RELATED: Raw Chicken For Dogs: Why I Stopped Feeding It …

Is Grape Seed Extract Good For Dogs?

Like grapeseed oil, grape seed extract isn’t toxic for your dog. A 2016 study tested an extract of blueberries and grapes and found it did not cause renal or liver damage.  

Grape seed extract (GSE) is an antioxidant. It scavenges free radicals to prevent cell damage and chronic disease.

The antioxidant found in GSE is oligomeric proanthocyanidin (OPC). Proanthocyanidin is a polyphenol that’s found in …

They’re responsible for the blue, red and purple colours.

OPCs help …

  • Improve blood flow
  • Reduce symptoms of diabetes
  • Ease swollen joints
  • Eye function

Research shows that GSE can slow and prevent canine cataracts.

So … Can Dogs Eat Grapes?

Dogs can have grapeseed oil (with caution) and grape seed extract … but they can’t eat grapes. Grapes are toxic to dogs.

If you want to give your dog the nutrients and antioxidants he misses out on because he can’t eat grapes, try …

These are full of antioxidants and vitamins to keep your dog happy and healthy!

5 minutes a day. Healthier Dog.

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