Our 3,5 month old lab puppy managed to steal a whole chocolate bar (180g milk chocolate) while we moved christmas packages around and ate it whole.
We force-fed a handful of salt to him immediately after noticing what had happened and he vomited almost all of it out. I called a vet and got instructions to give medicinal coal and monitor closely if any symptoms appear.
It’s been several hours now and he’s pretty much back to normal, a bit beaten up due to vomiting and upset stomach, but at least so far seems like nothing permanent happened. He’s got a vet scheduled anyways in few days for other stuff so he’ll get checked up at the same time.
I believe “chocolate”-y treats for dogs are made with carob, not cacao. Carob is safe for dogs. If you want to make chocolatey treats that will be safe if dogs consume them, and are tasty in their own right, you can use carob instead.
Edit to add: here’s a random link explaining that it’s the theobromine and caffeine in cacao that is toxic to dogs. Bonus, carob is a healthy alternative and packs quite a few nutrients for both humans and dogs: https://www.petscare.com/news/post/ultimate-guide-carob-dog-treats