Toxic Grapes and Winery Dogs

The biggest surprise of the year so far was the discovery that grapes can be highly toxic to dogs. Someone mentioned it on a breed mailing list I subscribe to, and sure enough a Google search on [grapes toxic dogs] reveals that even a single grape or raisin can cause severe reactions or death.

So I got a little nervous remembering that during homemade wine crush season the dogs are always around, and it's hard to keep track of every grape that leaves the crusher, and I've seen the smaller dog pick up a cluster and run around with it. This will stop next season, of course.

But I'm curious about the fact that nearly every winery has a beloved dog or two, there was even a photo book or calendar on winery dogs, and I don't recall ever hearing about their getting sick from grapes. Is this property of grapes well-known among vinters and growers? Has anyone's dog had unfortunate reactions during crush season? Surely someone would have noticed if the problem is as severe as the Google links indicate.

My guess is that grapes are not something dogs would find appealing, so they wouldn't eat them. They know better. Then again, there's Robin who has stated on more than one occasion that he doesn't like his grapes in pill form.

We discussed this (at length) a while back on a food/wine e-mail discussion list I am on.

Seems to me, like so much else, that for some dogs there is a problem, and for some, there is not. It seems to be possibly related to the weight of the dog and amount ingested. If you have a very small pooch and it eats a LOT of them, I'd be concerned. The odd grape or raisin here or there would not alarm me.

Of course, my 140 pound Great Pyrenees looks at grapes and says the canine equivalent of, "You actually eat those things?!"

My guess is that grapes are not something dogs would find appealing, so they wouldn't eat them.

Not necessarily the case. Some dogs love grapes. During crush at Linden Vineyards, the dogs were all over the place eating those that were falling off of the sorting table. They did eventually stop but I think it was because they were full and not for any other reason. They had been at it for over an hour.

Yeah, my dogs love sweets and 27 brix grapes are very, very sweet.

With so many dogs munching on dropped wine grapes and not hurting, I wonder whether there may be something different about table grapes that might make them more toxic.

And hey, Cynthia, I have a dog from the Pyrenees too, but the Great's little cousin, a petite Berger des Pyrenees. She's probably as big as your dog's paw.

Robert Parker told the story in one of his wine reviews of a producer in the Northern Rhone who has a dog that drinks wine from the wine thief. So apparently once fermented into wine the toxic element is eliminated.

-Paul W.

Thus far my loveable lab has liked every fruit he's come across except grapefruit. He won't move farther than 6-10 inches away from me if I have any form of melon, mango, peach, or berry and will wait completely without distraction to get as much of it as I can spare. He hasn't had grapes yet but I don't forsee a problem.

Chocolate is deadly for some dogs, but IME many dogs eat it and survive. I presume grapes are the same.

I've got an 11 year-old standard poodle. Every year, for the past 11, he bolts into the catawba vineyards nearby in October and gorges on grapes. He especially likes it when the mechanical harvester leaves the low-hanging clusters; in November, they are sweet and raisin-like.

In fact, when he was a puppy, I trained him to heel and take directions by using catawba clusters as a treat.

And he seems to love to fertilize the vineyard with recycled grape seeds...

When I heard about the dog allergy to grapes I almost cut him off, until I realized that he has been eating grapes all his life with no sign of them threatening to kill him!

Me, I don't eat grapes; don't even like them in juice form until after they are fermented.

My understanding is that grapes are much less of a problem than raisins. At present, I don't think anyone knows what the toxic element is.

Chocolate is deadly for some dogs, but IME many dogs eat it and survive. I presume grapes are the same.

Yes, I know I've heard people say they often give their dogs chocolate and never had a problem. We try hard to see the Basset never has chocolate or grapes. Better safe than sorry.

We live on our vineyard, and the vines begin where the lawn ends, so it's very easy for the dogs to wander. Have had 2 golden retreivers, one about 4 when we moved up there, and a puppy we got about 7 years ago. Angus, our old man, learned that towards the end of the growing season, the grapes seemed quite yummy and would go and help himself directly off the vines. He later taught (his) puppy this trick. In addition to eating grapes when they are close to ripe, they learned how to pick cucumbers and tomatoes right out of the garden.
So I'm guessing that some dogs might react to grapes, but perhaps not all.
Cheers !
Linda

Chocolate is deadly for some dogs, but IME many dogs eat it and survive. I presume grapes are the same.

The problem, I understand, is an alkaloid compound in chocolate Theobromannide, or something like that. Most light American "milk chocolate" and baked goods are quite low in this compound. Now...if your dog liked 80% dark cacao bars, that would be a problem

Chocolate is deadly for some dogs, but IME many dogs eat it and survive. I presume grapes are the same.

The problem, I understand, is an alkaloid compound in chocolate Theobromannide, or something like that. Most light American "milk chocolate" and baked goods are quite low in this compound. Now...if your dog liked 80% dark cacao bars, that would be a problem

It's theobromine and it can indeed be quite deadly for dogs. We've run samples from dead dogs where it was clear that the theobromine killed them. Some dogs will vomit up chocolate quickly enough that it won't hurt them and I suppose some may not be affected as easily as others. In general, though, one should work to keep one's dogs away from any chocolate.

It's theobromine and it can indeed be quite deadly for dogs. We've run samples from dead dogs where it was clear that the theobromine killed them. Some dogs will vomit up chocolate quickly enough that it won't hurt them and I suppose some may not be affected as easily as others. In general, though, one should work to keep one's dogs away from any chocolate.

Yup. Theobromine is a heart stimulant in humans as well as in dogs. The difference is that humans can metabolize theobromine whereas dogs cannot, leading to what amounts to an overdose. Apparently, something of the same sort occurs with grape skins, though my dog-loving biochemist friend didn't know what the component was that presented such a danger.

Mark Lipton

It's theobromine and it can indeed be quite deadly for dogs. We've run samples from dead dogs where it was clear that the theobromine killed them. Some dogs will vomit up chocolate quickly enough that it won't hurt them and I suppose some may not be affected as easily as others. In general, though, one should work to keep one's dogs away from any chocolate.

Yup. Theobromine is a heart stimulant in humans as well as in dogs. The difference is that humans can metabolize theobromine whereas dogs cannot, leading to what amounts to an overdose. Apparently, something of the same sort occurs with grape skins, though my dog-loving biochemist friend didn't know what the component was that presented such a danger.

Mark Lipton

Mark,

Apparently, it isn't known yet what the poison in grapes is that dogs react to with kidney failure.

Dogs have a similar reaction if they chew on holly, ivy, mistletoe, candles, and coal.

What's the common chemical thread?