On his website, Cesar Millan stated the following:
"I don't know what dogs dream, but they are definitely doing something really fun. Most of the time, their legs are moving, and they're barking. In all my years working with dogs - at one point, I had 65 dogs sleeping with me - I've never seen a dog panicking in the middle of his sleep. They just don't have nightmares like we do. You have to envy that!"
Based on his observations, of sleeping dogs he makes the statement, "They just don't have nightmares like we do."
This is flawed thinking, and is an example of an observation being stated as fact. Many dog training theories are stated as facts when, in fact, they are just observations or assumptions.
To scientifically state that dogs "Do not have nightmares like we do" you would have to define the following:
If you ever hear someone make a statement about dog behavior, do not believe it because they said it or because they have their own television show. Push them for research or ask about the science behind their statement. It is much different to have a theory or make an observation versus having proof.
Examples of statements that are widely used include:
Each of these statements might be true, but the statements have not been proven. Many trainers and dog owners have said things like this over the years so many times that they are part of the normal dog training lexicon. But, just because something is repeated many times does not make it true.
The earth is flat, right?