This is a old thread, over 3 years since last entry. I'm not sure what kind of response you are expecting...no response.
Now, about your statement. CBD (Cannabidiol) is obtained from Cannabis sativa. That fact alone doesn't make it safe automatically, for either dogs or humans.
Literally thousands of chemicals are "natural" (meaning they can be found in nature, free of human chemical modifications) and they have a wide range of effects over living creatures. From killing them instantly to healing them from a number of ailments.
The fact that CBD (which is not psychoactive) is 40% of the plant's extract, does not mean than the rest is harmless. The most important thing to consider is finding a provider that ensures the purity of the oil, where most or all of the psychoactive Cannabis chemicals (like THC) have been removed.