SQUICKY TALK OF PUKE BELOW:
The problem with inducing vomitting with people is not just that it makes them throw up, but that it makes people vomit *violently.* The throwing up itself isn't the problem - it's HOW you throw up.
We have had to use hydrogen peroxide with my sister Eli's dogs twice, and my Auggie once. Eli's dogs got into chocolate; Auggie is a whole other long story, but he got into something worse than chocolate, and there was a long horrified ten minutes where I thought my puppy was going to die, blah blah blah.
Anyway, when you give the dogs hydrogen peroxide, sometimes their mouths foam up a little. They walk around a little bit, sometimes they start eating grass to help it along. Pretty soon that start that hurk-hurk-hurk!! thing and throw up. Usually two or three times, depending on how much they have in their stomaches obviously. Then it's over.
Now, Eli's dogs have sensitive stomaches, so they throw up quite often to be frank! I can assure you when they threw up after we gave them the peroxide, it was *exactly* the same as when they throw up normally.
It is, indeed, perfectly fine. =>
Yes, it sounds awful when the vet tells you to pour hydrogen peroxide down their throat and make them throw up! But it's really not so bad.
The issue of "how much is too much" is also more than a simple "dog is X pounds, Y chocolate has Z amounts of thebromine" equation, because all dogs tend to react differently - and I think the situation is usually that a dog gets into a bag of candy and you can't even judge HOW much they ate! Clearly it's always better to prevent your dogs from eating chocolate than to deal with the consequences, but hey... you do what you can, right?