If you put D Con directly out without the bait station then the dog can get poisoned from the D Con poison and could die if not treated by a vet in a timely manner.
However if you use the D Con bait station it makes it safer to have the D Con around pets and children including dogs as the dog should not be able to get to the D Con poison to ingest it.
To poison a dog with rat poison it takes a lethal dose which consists of between 0.2 and 4 milligrams of brodifacoum for every kilogram of body weight.
I would still make sure to try and put the D Con or any other rat poison out of the reach of pets including the dog and watch your children closely so that they do not try to eat it.
Although D Con says it's not harmful to humans it's still not worth the chance and children should be taught to not put things like that in their mouths.