Your first mistake is (unintentionally) equating dogs with kids. They are not even remotely the same. Kids continue to grow intellectually and can learn to understand nebulous concepts. While bright and able to understand a multitude of words, dogs are still very limited from a cognitive standpoint.
I have a sister who used to drug her dog whenever they took long trips in the car. The dog actually started to build up a tolerance to it, so the vet had to up the dosage. That poor dog was drooling profusely and so loopy, I felt genuinely bad for it. She refused to get it a simple car seat belt (special dog harness), which not only calms them in the car (since they can't move as much), but is so much safer for them for a multitude of reasons. That dog was her kid. I would never treat any kid like that. My wife had a dog when we first started dating who was spastic as hell when the dog got in the car. My wife was furious when I got the dog seat belt because she couldn't hold and comfort her, until she saw the dog actually calm down.
My point is, dogs are not actually kids. They require different training, and if you're not willing to learn and apply it you are actually doing them a disservice.