I brush them. The toothbrush doesn't really matter, although ones made speficially for dogs are often angled so as to reach their back teeth easier. Don't use human toothpaste however. They sell dog toothpaste that are flavored so the dogs enjoy it. Human toothpaste isn't meant to be consumed, and you can't make a dog spit it out . So definitely use toothpaste that is made for dogs. I brush my pups' teeth once a week and they also get chews to help keep them clean.