Meaning what? Say no to having a dog? Or saying no to the dog verbally? Because I have taught my dog "no". She, however, is ignoring me at the moment with the new babies. So I've had to add "go lay down" to the no in order to get her to leave them alone. I'm going to have to lock them up in the spare bedroom at night since I can't take the risk of her possibly hurting them while we sleep. That's why I want her to get used to them and understand they are not for play or for food so I don't have to watch her like a hawk.
As for if you meant say no to HAVING a dog, that's out of the question. Kalli is my hubby's baby, a 4.5 year old chocolate lab, and no way in hades will he get rid of his dog for my chickens.
Now, if we were talking about my baby, Shelby (she's the one in my avatar), I wouldn't have an issue. Shelby would curl up with them and treat them like her own babies. She was an Australian Shepherd mix, and I lost her the beginning of January after 11 years of loving companionship.