Just kidding. Grapes have lots of tartaric acid and, accordingly to this link, tartaric acid causes kidney failure in dogs.
Then accordingly to this link only 15~20% of the tartaric acid consumed by humans is eliminated in the urine; most of it goes to the large intestine, and gets metabolised by bacteria. So I guess that, unlike dogs, we avoid the kidney failure by avoiding sending it to the kidneys.
This is the first result when I search with Kagi, so maybe you should switch your search engine. With Google's degrading performance you hear more and more about alternative engines, for example Qwant and Metager are based in the EU and care a bit more about your privacy than their profit in comparison to Google.
Every plant is poisonous. Humans are basically the only mammal that eats capsaicin, caffeine, menthol. Grapes are toxic for everything except a few things. Plants don't have the ability to pull out a gun to defend itself and so it uses poison, or irritants like thorns. This isn't limited to pants with animals. Plants are also toxic to other plants. The example that I deal with the most is black walnut. I tried growing plants and when I used the walnut leaves for mulch it would kill the plants I tried growing.
Seriously, everyone points to our brains and thumbs as to why we're the dominant species on the planet, but our ability to eat damn near everything is also a major factor. We can eat a wide range of plants and animals native to every region of every continent. Wolves/dogs are our closest competition there and they can only eat a fraction of what we can eat. This made us completely unlimited in where we could go and colonize way back in the stone age.
What I don’t get is how there seem to be only a few remaining food types that people of certain ethnicities can’t tolerate. Like, some people can’t tolerate cow milk, some can’t tolerate wheat, because they didn’t have those things thousands of years ago. But like, most of the planet didn’t have most of the types of food available now until relatively recently, so why don’t you hear of more people being allergic to tomatoes, potatoes, mustard, etc?
Humans are basically the only mammal that eats capsaicin
I had a dog who liked pepper sauce.
Story time: I was 14 or so. Eating fish patties. As usual, drowning them in pepper sauce. Lana (my dog, a mid-large poodle) kept nagging me for food, it was annoying. I offered her a tiny bit of the patty, with pepper sauce. I expected her to smell it and think "eeew, humans eat this? Human food is inedible!". Instead she ate it, licked the floor, and asked me more.
This is amazing to me. We're immune to so many things that are dangerous/toxic/deadly to other biological life on the planet. We've evolved to an amazing extent, and yet, pick the wrong variety of berry and you'll die writhing in agony.
They're all trying to kill you, it's just that some of them, still can.
You can't be immune to everything and it all comes down to your genetics (lactose intolerance being the most famous example) and what you ate since childhood. One extreme example of what some groups of people can eat is kopalhen, which is deeply fermented meat full of ptomaines, which will kill most humans very fast. It also comes with botulism risk.
Most dogs are fine actually. A small seemingly random percentage go into kidney failure so it's easier and more humane to just not take a chance.
In a similar vein as your dogs but in Asian countries the dogs also eat/get fed leftovers which include plenty of spices, which are also stated online as problematic for dogs.
Recent research indicates it might be differences in the grapes, not differences in the dogs. Different breeds of grapes have different levels of certain chemicals that are toxic to dogs.
Yep. We grew grapes too, multiple varieties. Dogs ate them and had zero ill effects. One of them even stole one of those 1 lb chocolate bars and ate it, the worst effect was a little diarrhea.
Some of these things are way overblown on the internet. OMG your St Bernard ate a grape?!? I’m sure a lot of it has to do with dog weight vs quantity consumed, so a bunch of chocolate for a Chihuahua is a different story vs a German Shepherd. I’m not suggesting it’s OK for dogs to eat these things, just exercise some judgement and call a vet, but the internet freakout is unreasonable.