Why is it apple seeds are bad for dogs?

TIA

they are poisinous. I'm not sure the quantity they'd have to eat, though.

They are poisonous. Apple wood for burning also gives off toxic fumes....I was told to put in a mix of other woods if you are burning apple wood. Apple wood burns very hot, so a desirable wood, but caution is advised.

I believe they contain trace amounts of arsenic, but I may be confusing them with almonds...

it's cyanide.

gcb,md

Although apple pips contain amygdalin which metabolizes into hydrogen cyanide, the canine and human body can detoxify cyanide in the kind of doses likely to be ingested. Even birds can handle the few seeds contained in a non-cored apple.

Also, apple pips have a hard outer coating and dogs tend to swallow them whole. Unless they are chewed and broken down, the amygdalin is not released.

The only foreseeable problem could be the unwanted planting of apple trees in your garden from undigested pips in dog stool !!