[declan_roberts]

I live in a rural area and I'm surprised at how well grazing animals intuitively avoid these poisonous plants.

I see goats grazing in fields with hemlock. They'll give the hemlock a sniff and then avoid it while greedily eating everything else around it.

[m463]

Growing up, I remember throwing my dog food. It was just amazing, the food would arch up, intersect with his mouth, and just... disappear.

except grapes. They would arch up, intersect with his mouth, and... hit a tongue and roll off onto the floor.

turns out grapes (and raisins) are toxic to dogs. How they figure that out during the millisecond encounter with the tongue is mind-boggling.

oh, another one: one time when young I gave my dog a corncob to chew on, my theory being it would be like gnawing on a bone. and it he just ate it. it disappeared. we monitored him, he was fine, but scared me to death.

[florbo]

iirc it's the concentration of tartaric acid that's toxic to dogs. You got lucky your dog didn't like grapes! A lot of dogs will just eat them, btw, so don't think they all will instinctively avoid grapes.

[Johnythree]

I'm puzzled by this claim. I wouldn't call it a myth, but all the same...

I grew up on a vineyard. Each harvest time the grapes would hang down heavily and almost touch the ground. Our pet dogs would park themselves beneath and greedily consume a whole bunch.

They would also scoff any dried grapes they found on the ground.

The worst effect seemed that they all would get noticeably pudgy during the season.

[florbo]

The concentration of tartaric acid in each individual grape is unpredictable, along with each individual dog's tolerance level to tartaric acid. The only thing that's certain is that anything with tartaric acid is potentially toxic to canines due the development kidney damage after ingestion.