Advice Asap plz...one of my dogs at half of huge dark chocolate bar...will they be ok

I left a huge chocolate bar and one of my dogs ate it!!! My mom says it can kill them and that its toxic...one of my dogs is a jack russell and one is a little chiuahua. I am afraid of whats gonna happen...does anyone know?

 

Chocolate is toxic for dogs. My dog has eaten half of a chocolate bar before that I accidently left out and she was fine. I think your dog will be ok.........my dog has eaten much more chocolate in her lifetime than just a half of a bar (by accident on my part of course) and she's just fine. But keep an eye on her, and if you notice anything strange then call a vet.